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1594 lines
53 KiB
JavaScript
1594 lines
53 KiB
JavaScript
/* eslint no-console: 0 */
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/* global console */
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"use strict";
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let peg = require("../../lib/peg");
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describe("generated parser behavior", function() {
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function varyOptimizationOptions(block) {
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function clone(object) {
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let result = {}, key;
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for (key in object) {
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if (object.hasOwnProperty(key)) {
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result[key] = object[key];
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}
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}
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return result;
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}
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let optionsVariants = [
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{ cache: false, optimize: "speed", trace: false },
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{ cache: false, optimize: "speed", trace: true },
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{ cache: false, optimize: "size", trace: false },
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{ cache: false, optimize: "size", trace: true },
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{ cache: true, optimize: "speed", trace: false },
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{ cache: true, optimize: "speed", trace: true },
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{ cache: true, optimize: "size", trace: false },
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{ cache: true, optimize: "size", trace: true }
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];
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optionsVariants.forEach(function(variant) {
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describe(
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"with options " + jasmine.pp(variant),
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function() { block(clone(variant)); }
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);
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});
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}
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beforeEach(function() {
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this.addMatchers({
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toParse: function(input, expected, options) {
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options = options !== undefined ? options : {};
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let result;
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try {
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result = this.actual.parse(input, options);
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} catch (e) {
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this.message = function() {
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return "Expected " + jasmine.pp(input) + " "
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+ "with options " + jasmine.pp(options) + " "
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+ "to parse" + (expected !== undefined ? " as " + jasmine.pp(expected) : "") + ", "
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+ "but it failed to parse with message "
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+ jasmine.pp(e.message) + ".";
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};
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return false;
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}
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if (expected !== undefined) {
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this.message = function() {
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return "Expected " + jasmine.pp(input) + " "
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+ "with options " + jasmine.pp(options) + " "
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+ (this.isNot ? "not " : "")
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+ "to parse as " + jasmine.pp(expected) + ", "
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+ "but it parsed as " + jasmine.pp(result) + ".";
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};
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return this.env.equals_(result, expected);
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} else {
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return true;
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}
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},
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toFailToParse: function(input, details, options) {
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options = options !== undefined ? options : {};
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let result, key;
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try {
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result = this.actual.parse(input, options);
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} catch (e) {
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if (this.isNot) {
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this.message = function() {
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return "Expected " + jasmine.pp(input)
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+ "with options " + jasmine.pp(options) + " "
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+ "to parse, "
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+ "but it failed with message "
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+ jasmine.pp(e.message) + ".";
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};
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} else {
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if (details) {
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for (key in details) {
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if (details.hasOwnProperty(key)) {
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if (!this.env.equals_(e[key], details[key])) {
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this.message = function() {
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return "Expected " + jasmine.pp(input) + " "
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+ "with options " + jasmine.pp(options) + " "
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+ "to fail to parse"
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+ (details ? " with details " + jasmine.pp(details) : "") + ", "
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+ "but " + jasmine.pp(key) + " "
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+ "is " + jasmine.pp(e[key]) + ".";
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};
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return false;
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}
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}
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}
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}
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}
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return true;
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}
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this.message = function() {
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return "Expected " + jasmine.pp(input) + " "
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+ "with options " + jasmine.pp(options) + " "
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+ "to fail to parse"
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+ (details ? " with details " + jasmine.pp(details) : "") + ", "
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+ "but it parsed as " + jasmine.pp(result) + ".";
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};
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return false;
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}
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});
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/*
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* Stub out |console.log| so that the default tracer doesn't clutter
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* test output.
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*/
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if (typeof console === "object") {
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spyOn(console, "log");
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}
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});
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varyOptimizationOptions(function(options) {
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describe("initializer", function() {
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it("executes the code before parsing starts", function() {
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let parser = peg.generate([
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'{ var result = 42; }',
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'start = "a" { return result; }'
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].join("\n"), options);
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expect(parser).toParse("a", 42);
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});
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describe("available variables and functions", function() {
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it("|options| contains options", function() {
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let parser = peg.generate([
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'{ var result = options; }',
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'start = "a" { return result; }'
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].join("\n"), options);
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expect(parser).toParse("a", { a: 42 }, { a: 42 });
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});
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});
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});
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describe("rule", function() {
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if (options.cache) {
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it("caches rule match results", function() {
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let parser = peg.generate([
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'{ var n = 0; }',
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'start = (a "b") / (a "c") { return n; }',
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'a = "a" { n++; }'
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].join("\n"), options);
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expect(parser).toParse("ac", 1);
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});
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} else {
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it("doesn't cache rule match results", function() {
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let parser = peg.generate([
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'{ var n = 0; }',
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'start = (a "b") / (a "c") { return n; }',
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'a = "a" { n++; }'
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].join("\n"), options);
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expect(parser).toParse("ac", 2);
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});
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}
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describe("when the expression matches", function() {
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it("returns its match result", function() {
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let parser = peg.generate('start = "a"');
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expect(parser).toParse("a", "a");
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});
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});
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describe("when the expression doesn't match", function() {
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describe("without display name", function() {
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it("reports match failure and doesn't record any expectation", function() {
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let parser = peg.generate('start = "a"');
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expect(parser).toFailToParse("b", {
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expected: [{ type: "literal", text: "a", ignoreCase: false }]
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});
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});
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});
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describe("with display name", function() {
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it("reports match failure and records an expectation of type \"other\"", function() {
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let parser = peg.generate('start "start" = "a"');
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expect(parser).toFailToParse("b", {
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expected: [{ type: "other", description: "start" }]
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});
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});
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it("discards any expectations recorded when matching the expression", function() {
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let parser = peg.generate('start "start" = "a"');
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expect(parser).toFailToParse("b", {
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expected: [{ type: "other", description: "start" }]
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});
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});
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});
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});
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});
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describe("literal", function() {
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describe("matching", function() {
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it("matches empty literals", function() {
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let parser = peg.generate('start = ""', options);
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expect(parser).toParse("");
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});
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it("matches one-character literals", function() {
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let parser = peg.generate('start = "a"', options);
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expect(parser).toParse("a");
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expect(parser).toFailToParse("b");
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});
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it("matches multi-character literals", function() {
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let parser = peg.generate('start = "abcd"', options);
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expect(parser).toParse("abcd");
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expect(parser).toFailToParse("efgh");
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});
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it("is case sensitive without the \"i\" flag", function() {
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let parser = peg.generate('start = "a"', options);
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expect(parser).toParse("a");
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expect(parser).toFailToParse("A");
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});
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it("is case insensitive with the \"i\" flag", function() {
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let parser = peg.generate('start = "a"i', options);
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expect(parser).toParse("a");
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expect(parser).toParse("A");
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});
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});
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describe("when it matches", function() {
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it("returns the matched text", function() {
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let parser = peg.generate('start = "a"', options);
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expect(parser).toParse("a", "a");
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});
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it("consumes the matched text", function() {
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let parser = peg.generate('start = "a" .', options);
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expect(parser).toParse("ab");
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});
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});
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describe("when it doesn't match", function() {
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it("reports match failure and records an expectation of type \"literal\"", function() {
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let parser = peg.generate('start = "a"', options);
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expect(parser).toFailToParse("b", {
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expected: [{ type: "literal", text: "a", ignoreCase: false }]
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});
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});
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});
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});
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describe("character class", function() {
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describe("matching", function() {
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it("matches empty classes", function() {
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let parser = peg.generate('start = []', options);
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expect(parser).toFailToParse("a");
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});
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it("matches classes with a character list", function() {
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let parser = peg.generate('start = [abc]', options);
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expect(parser).toParse("a");
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expect(parser).toParse("b");
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expect(parser).toParse("c");
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expect(parser).toFailToParse("d");
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});
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it("matches classes with a character range", function() {
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let parser = peg.generate('start = [a-c]', options);
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expect(parser).toParse("a");
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expect(parser).toParse("b");
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expect(parser).toParse("c");
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expect(parser).toFailToParse("d");
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});
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it("matches inverted classes", function() {
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let parser = peg.generate('start = [^a]', options);
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expect(parser).toFailToParse("a");
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expect(parser).toParse("b");
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});
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it("is case sensitive without the \"i\" flag", function() {
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let parser = peg.generate('start = [a]', options);
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expect(parser).toParse("a");
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expect(parser).toFailToParse("A");
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});
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it("is case insensitive with the \"i\" flag", function() {
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let parser = peg.generate('start = [a]i', options);
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expect(parser).toParse("a");
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expect(parser).toParse("A");
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});
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});
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describe("when it matches", function() {
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it("returns the matched character", function() {
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let parser = peg.generate('start = [a]', options);
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expect(parser).toParse("a", "a");
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});
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it("consumes the matched character", function() {
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let parser = peg.generate('start = [a] .', options);
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expect(parser).toParse("ab");
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});
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});
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describe("when it doesn't match", function() {
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it("reports match failure and records an expectation of type \"class\"", function() {
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let parser = peg.generate('start = [a]', options);
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expect(parser).toFailToParse("b", {
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expected: [{ type: "class", parts: ["a"], inverted: false, ignoreCase: false }]
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});
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});
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});
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});
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describe("dot", function() {
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describe("matching", function() {
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it("matches any character", function() {
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let parser = peg.generate('start = .', options);
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expect(parser).toParse("a");
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expect(parser).toParse("b");
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expect(parser).toParse("c");
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});
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});
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describe("when it matches", function() {
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it("returns the matched character", function() {
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let parser = peg.generate('start = .', options);
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expect(parser).toParse("a", "a");
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});
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it("consumes the matched character", function() {
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let parser = peg.generate('start = . .', options);
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expect(parser).toParse("ab");
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});
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});
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describe("when it doesn't match", function() {
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it("reports match failure and records an expectation of type \"any\"", function() {
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let parser = peg.generate('start = .', options);
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expect(parser).toFailToParse("", {
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expected: [{ type: "any" }]
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});
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});
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});
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});
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describe("rule reference", function() {
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describe("when referenced rule's expression matches", function() {
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it("returns its result", function() {
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let parser = peg.generate([
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'start = a',
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'a = "a"'
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].join("\n"), options);
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expect(parser).toParse("a", "a");
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});
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});
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describe("when referenced rule's expression doesn't match", function() {
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it("reports match failure", function() {
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let parser = peg.generate([
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'start = a',
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'a = "a"'
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].join("\n"), options);
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expect(parser).toFailToParse("b");
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});
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});
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});
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describe("positive semantic predicate", function() {
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describe("when the code returns a truthy value", function() {
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it("returns |undefined|", function() {
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/*
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* The |""| is needed so that the parser doesn't return just
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* |undefined| which we can't compare against in |toParse| due to the
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* way optional parameters work.
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*/
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let parser = peg.generate('start = &{ return true; } ""', options);
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expect(parser).toParse("", [undefined, ""]);
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});
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});
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describe("when the code returns a falsey value", function() {
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it("reports match failure", function() {
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let parser = peg.generate('start = &{ return false; }', options);
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expect(parser).toFailToParse("");
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});
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});
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describe("label variables", function() {
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describe("in containing sequence", function() {
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it("can access variables defined by preceding labeled elements", function() {
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let parser = peg.generate(
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'start = a:"a" &{ return a === "a"; }',
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options
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);
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expect(parser).toParse("a");
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});
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it("cannot access variable defined by labeled predicate element", function() {
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let parser = peg.generate(
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'start = "a" b:&{ return b === undefined; } "c"',
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options
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);
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expect(parser).toFailToParse("ac");
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});
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|
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it("cannot access variables defined by following labeled elements", function() {
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let parser = peg.generate(
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'start = &{ return a === "a"; } a:"a"',
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options
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);
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expect(parser).toFailToParse("a");
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});
|
|
|
|
it("cannot access variables defined by subexpressions", function() {
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|
let testcases = [
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{
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grammar: 'start = (a:"a") &{ return a === "a"; }',
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input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")? &{ return a === "a"; }',
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input: "a"
|
|
},
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|
{
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grammar: 'start = (a:"a")* &{ return a === "a"; }',
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input: "a"
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|
},
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|
{
|
|
grammar: 'start = (a:"a")+ &{ return a === "a"; }',
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|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = $(a:"a") &{ return a === "a"; }',
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|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = &(a:"a") "a" &{ return a === "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = !(a:"a") "b" &{ return a === "a"; }',
|
|
input: "b"
|
|
},
|
|
{
|
|
grammar: 'start = b:(a:"a") &{ return a === "a"; }',
|
|
input: "a"
|
|
},
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|
{
|
|
grammar: 'start = ("a" b:"b" "c") &{ return b === "b"; }',
|
|
input: "abc"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a" { return a; }) &{ return a === "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = ("a" / b:"b" / "c") &{ return b === "b"; }',
|
|
input: "b"
|
|
}
|
|
],
|
|
parser;
|
|
|
|
testcases.forEach(function(testcase) {
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|
parser = peg.generate(testcase.grammar, options);
|
|
expect(parser).toFailToParse(testcase.input);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("in outer sequence", function() {
|
|
it("can access variables defined by preceding labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = a:"a" ("b" &{ return a === "a"; })',
|
|
options
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|
);
|
|
|
|
expect(parser).toParse("ab");
|
|
});
|
|
|
|
it("cannot access variable defined by labeled predicate element", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" b:("b" &{ return b === undefined; }) "c"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("abc");
|
|
});
|
|
|
|
it("cannot access variables defined by following labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = ("a" &{ return b === "b"; }) b:"b"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("ab");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("initializer variables & functions", function() {
|
|
it("can access variables defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ var v = 42 }',
|
|
'start = &{ return v === 42; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("");
|
|
});
|
|
|
|
it("can access functions defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ function f() { return 42; } }',
|
|
'start = &{ return f() === 42; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("");
|
|
});
|
|
});
|
|
|
|
describe("available variables & functions", function() {
|
|
it("|options| contains options", function() {
|
|
let parser = peg.generate([
|
|
'{ var result; }',
|
|
'start = &{ result = options; return true; } { return result; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("", { a: 42 }, { a: 42 });
|
|
});
|
|
|
|
it("|location| returns current location info", function() {
|
|
let parser = peg.generate([
|
|
'{ var result; }',
|
|
'start = line (nl+ line)* { return result; }',
|
|
'line = thing (" "+ thing)*',
|
|
'thing = digit / mark',
|
|
'digit = [0-9]',
|
|
'mark = &{ result = location(); return true; } "x"',
|
|
'nl = "\\r"? "\\n"'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("1\n2\n\n3\n\n\n4 5 x", {
|
|
start: { offset: 13, line: 7, column: 5 },
|
|
end: { offset: 13, line: 7, column: 5 }
|
|
});
|
|
|
|
/* Newline representations */
|
|
expect(parser).toParse("1\nx", { // Unix
|
|
start: { offset: 2, line: 2, column: 1 },
|
|
end: { offset: 2, line: 2, column: 1 }
|
|
});
|
|
expect(parser).toParse("1\r\nx", { // Windows
|
|
start: { offset: 3, line: 2, column: 1 },
|
|
end: { offset: 3, line: 2, column: 1 }
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("negative semantic predicate", function() {
|
|
describe("when the code returns a falsey value", function() {
|
|
it("returns |undefined|", function() {
|
|
/*
|
|
* The |""| is needed so that the parser doesn't return just
|
|
* |undefined| which we can't compare against in |toParse| due to the
|
|
* way optional parameters work.
|
|
*/
|
|
let parser = peg.generate('start = !{ return false; } ""', options);
|
|
|
|
expect(parser).toParse("", [undefined, ""]);
|
|
});
|
|
});
|
|
|
|
describe("when the code returns a truthy value", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = !{ return true; }', options);
|
|
|
|
expect(parser).toFailToParse("");
|
|
});
|
|
});
|
|
|
|
describe("label variables", function() {
|
|
describe("in containing sequence", function() {
|
|
it("can access variables defined by preceding labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = a:"a" !{ return a !== "a"; }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("a");
|
|
});
|
|
|
|
it("cannot access variable defined by labeled predicate element", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" b:!{ return b !== undefined; } "c"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("ac");
|
|
});
|
|
|
|
it("cannot access variables defined by following labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = !{ return a !== "a"; } a:"a"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("a");
|
|
});
|
|
|
|
it("cannot access variables defined by subexpressions", function() {
|
|
let testcases = [
|
|
{
|
|
grammar: 'start = (a:"a") !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")? !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")* !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")+ !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = $(a:"a") !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = &(a:"a") "a" !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = !(a:"a") "b" !{ return a !== "a"; }',
|
|
input: "b"
|
|
},
|
|
{
|
|
grammar: 'start = b:(a:"a") !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = ("a" b:"b" "c") !{ return b !== "b"; }',
|
|
input: "abc"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a" { return a; }) !{ return a !== "a"; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = ("a" / b:"b" / "c") !{ return b !== "b"; }',
|
|
input: "b"
|
|
}
|
|
],
|
|
parser;
|
|
|
|
testcases.forEach(function(testcase) {
|
|
parser = peg.generate(testcase.grammar, options);
|
|
expect(parser).toFailToParse(testcase.input);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("in outer sequence", function() {
|
|
it("can access variables defined by preceding labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = a:"a" ("b" !{ return a !== "a"; })',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("ab");
|
|
});
|
|
|
|
it("cannot access variable defined by labeled predicate element", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" b:("b" !{ return b !== undefined; }) "c"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("abc");
|
|
});
|
|
|
|
it("cannot access variables defined by following labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = ("a" !{ return b !== "b"; }) b:"b"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("ab");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("initializer variables & functions", function() {
|
|
it("can access variables defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ var v = 42 }',
|
|
'start = !{ return v !== 42; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("");
|
|
});
|
|
|
|
it("can access functions defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ function f() { return 42; } }',
|
|
'start = !{ return f() !== 42; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("");
|
|
});
|
|
});
|
|
|
|
describe("available variables & functions", function() {
|
|
it("|options| contains options", function() {
|
|
let parser = peg.generate([
|
|
'{ var result; }',
|
|
'start = !{ result = options; return false; } { return result; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("", { a: 42 }, { a: 42 });
|
|
});
|
|
|
|
it("|location| returns current location info", function() {
|
|
let parser = peg.generate([
|
|
'{ var result; }',
|
|
'start = line (nl+ line)* { return result; }',
|
|
'line = thing (" "+ thing)*',
|
|
'thing = digit / mark',
|
|
'digit = [0-9]',
|
|
'mark = !{ result = location(); return false; } "x"',
|
|
'nl = "\\r"? "\\n"'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("1\n2\n\n3\n\n\n4 5 x", {
|
|
start: { offset: 13, line: 7, column: 5 },
|
|
end: { offset: 13, line: 7, column: 5 }
|
|
});
|
|
|
|
/* Newline representations */
|
|
expect(parser).toParse("1\nx", { // Unix
|
|
start: { offset: 2, line: 2, column: 1 },
|
|
end: { offset: 2, line: 2, column: 1 }
|
|
});
|
|
expect(parser).toParse("1\r\nx", { // Windows
|
|
start: { offset: 3, line: 2, column: 1 },
|
|
end: { offset: 3, line: 2, column: 1 }
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("group", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns its match result", function() {
|
|
let parser = peg.generate('start = ("a")', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = ("a")', options);
|
|
|
|
expect(parser).toFailToParse("b");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("optional", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns its match result", function() {
|
|
let parser = peg.generate('start = "a"?', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("returns |null|", function() {
|
|
let parser = peg.generate('start = "a"?', options);
|
|
|
|
expect(parser).toParse("", null);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("zero or more", function() {
|
|
describe("when the expression matches zero or more times", function() {
|
|
it("returns an array of its match results", function() {
|
|
let parser = peg.generate('start = "a"*', options);
|
|
|
|
expect(parser).toParse("", []);
|
|
expect(parser).toParse("a", ["a"]);
|
|
expect(parser).toParse("aaa", ["a", "a", "a"]);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("one or more", function() {
|
|
describe("when the expression matches one or more times", function() {
|
|
it("returns an array of its match results", function() {
|
|
let parser = peg.generate('start = "a"+', options);
|
|
|
|
expect(parser).toParse("a", ["a"]);
|
|
expect(parser).toParse("aaa", ["a", "a", "a"]);
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = "a"+', options);
|
|
|
|
expect(parser).toFailToParse("");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("text", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns the matched text", function() {
|
|
let parser = peg.generate('start = $("a" "b" "c")', options);
|
|
|
|
expect(parser).toParse("abc", "abc");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = $("a")', options);
|
|
|
|
expect(parser).toFailToParse("b");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("positive simple predicate", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns |undefined|", function() {
|
|
let parser = peg.generate('start = &"a" "a"', options);
|
|
|
|
expect(parser).toParse("a", [undefined, "a"]);
|
|
});
|
|
|
|
it("resets parse position", function() {
|
|
let parser = peg.generate('start = &"a" "a"', options);
|
|
|
|
expect(parser).toParse("a");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = &"a"', options);
|
|
|
|
expect(parser).toFailToParse("b");
|
|
});
|
|
|
|
it("discards any expectations recorded when matching the expression", function() {
|
|
let parser = peg.generate('start = "a" / &"b" / "c"', options);
|
|
|
|
expect(parser).toFailToParse("d", {
|
|
expected: [
|
|
{ type: "literal", text: "a", ignoreCase: false },
|
|
{ type: "literal", text: "c", ignoreCase: false }
|
|
]
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("negative simple predicate", function() {
|
|
describe("when the expression matches", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = !"a"', options);
|
|
|
|
expect(parser).toFailToParse("a");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("returns |undefined|", function() {
|
|
let parser = peg.generate('start = !"a" "b"', options);
|
|
|
|
expect(parser).toParse("b", [undefined, "b"]);
|
|
});
|
|
|
|
it("resets parse position", function() {
|
|
let parser = peg.generate('start = !"a" "b"', options);
|
|
|
|
expect(parser).toParse("b");
|
|
});
|
|
|
|
it("discards any expectations recorded when matching the expression", function() {
|
|
let parser = peg.generate('start = "a" / !"b" / "c"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
expected: [
|
|
{ type: "literal", text: "a", ignoreCase: false },
|
|
{ type: "literal", text: "c", ignoreCase: false }
|
|
]
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("label", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns its match result", function() {
|
|
let parser = peg.generate('start = a:"a"', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = a:"a"', options);
|
|
|
|
expect(parser).toFailToParse("b");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("sequence", function() {
|
|
describe("when all expressions match", function() {
|
|
it("returns an array of their match results", function() {
|
|
let parser = peg.generate('start = "a" "b" "c"', options);
|
|
|
|
expect(parser).toParse("abc", ["a", "b", "c"]);
|
|
});
|
|
});
|
|
|
|
describe("when any expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = "a" "b" "c"', options);
|
|
|
|
expect(parser).toFailToParse("dbc");
|
|
expect(parser).toFailToParse("adc");
|
|
expect(parser).toFailToParse("abd");
|
|
});
|
|
|
|
it("resets parse position", function() {
|
|
let parser = peg.generate('start = "a" "b" / "a"', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("action", function() {
|
|
describe("when the expression matches", function() {
|
|
it("returns the value returned by the code", function() {
|
|
let parser = peg.generate('start = "a" { return 42; }', options);
|
|
|
|
expect(parser).toParse("a", 42);
|
|
});
|
|
|
|
describe("label variables", function() {
|
|
describe("in the expression", function() {
|
|
it("can access variable defined by labeled expression", function() {
|
|
let parser = peg.generate('start = a:"a" { return a; }', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
|
|
it("can access variables defined by labeled sequence elements", function() {
|
|
let parser = peg.generate(
|
|
'start = a:"a" b:"b" c:"c" { return [a, b, c]; }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("abc", ["a", "b", "c"]);
|
|
});
|
|
|
|
it("cannot access variables defined by subexpressions", function() {
|
|
let testcases = [
|
|
{
|
|
grammar: 'start = (a:"a") { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")? { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")* { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a")+ { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = $(a:"a") { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = &(a:"a") "a" { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = !(a:"a") "b" { return a; }',
|
|
input: "b"
|
|
},
|
|
{
|
|
grammar: 'start = b:(a:"a") { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = ("a" b:"b" "c") { return b; }',
|
|
input: "abc"
|
|
},
|
|
{
|
|
grammar: 'start = (a:"a" { return a; }) { return a; }',
|
|
input: "a"
|
|
},
|
|
{
|
|
grammar: 'start = ("a" / b:"b" / "c") { return b; }',
|
|
input: "b"
|
|
}
|
|
],
|
|
parser;
|
|
|
|
testcases.forEach(function(testcase) {
|
|
parser = peg.generate(testcase.grammar, options);
|
|
expect(parser).toFailToParse(testcase.input);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("in outer sequence", function() {
|
|
it("can access variables defined by preceding labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = a:"a" ("b" { return a; })',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("ab", ["a", "a"]);
|
|
});
|
|
|
|
it("cannot access variable defined by labeled action element", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" b:("b" { return b; }) c:"c"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("abc");
|
|
});
|
|
|
|
it("cannot access variables defined by following labeled elements", function() {
|
|
let parser = peg.generate(
|
|
'start = ("a" { return b; }) b:"b"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("ab");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("initializer variables & functions", function() {
|
|
it("can access variables defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ var v = 42 }',
|
|
'start = "a" { return v; }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("a", 42);
|
|
});
|
|
|
|
it("can access functions defined in the initializer", function() {
|
|
let parser = peg.generate([
|
|
'{ function f() { return 42; } }',
|
|
'start = "a" { return f(); }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("a", 42);
|
|
});
|
|
});
|
|
|
|
describe("available variables & functions", function() {
|
|
it("|options| contains options", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" { return options; }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("a", { a: 42 }, { a: 42 });
|
|
});
|
|
|
|
it("|text| returns text matched by the expression", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" { return text(); }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
});
|
|
|
|
it("|location| returns location info of the expression", function() {
|
|
let parser = peg.generate([
|
|
'{ var result; }',
|
|
'start = line (nl+ line)* { return result; }',
|
|
'line = thing (" "+ thing)*',
|
|
'thing = digit / mark',
|
|
'digit = [0-9]',
|
|
'mark = "x" { result = location(); }',
|
|
'nl = "\\r"? "\\n"'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("1\n2\n\n3\n\n\n4 5 x", {
|
|
start: { offset: 13, line: 7, column: 5 },
|
|
end: { offset: 14, line: 7, column: 6 }
|
|
});
|
|
|
|
/* Newline representations */
|
|
expect(parser).toParse("1\nx", { // Unix
|
|
start: { offset: 2, line: 2, column: 1 },
|
|
end: { offset: 3, line: 2, column: 2 }
|
|
});
|
|
expect(parser).toParse("1\r\nx", { // Windows
|
|
start: { offset: 3, line: 2, column: 1 },
|
|
end: { offset: 4, line: 2, column: 2 }
|
|
});
|
|
});
|
|
|
|
describe("|expected|", function() {
|
|
it("terminates parsing and throws an exception", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" { expected("a"); }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("a", {
|
|
message: 'Expected a but "a" found.',
|
|
expected: [{ type: "other", description: "a" }],
|
|
found: "a",
|
|
location: {
|
|
start: { offset: 0, line: 1, column: 1 },
|
|
end: { offset: 1, line: 1, column: 2 }
|
|
}
|
|
});
|
|
});
|
|
|
|
it("allows to set custom location info", function() {
|
|
let parser = peg.generate([
|
|
'start = "a" {',
|
|
' expected("a", {',
|
|
' start: { offset: 1, line: 1, column: 2 },',
|
|
' end: { offset: 2, line: 1, column: 3 }',
|
|
' });',
|
|
'}'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toFailToParse("a", {
|
|
message: 'Expected a but "a" found.',
|
|
expected: [{ type: "other", description: "a" }],
|
|
found: "a",
|
|
location: {
|
|
start: { offset: 1, line: 1, column: 2 },
|
|
end: { offset: 2, line: 1, column: 3 }
|
|
}
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("|error|", function() {
|
|
it("terminates parsing and throws an exception", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" { error("a"); }',
|
|
options
|
|
);
|
|
|
|
expect(parser).toFailToParse("a", {
|
|
message: "a",
|
|
found: null,
|
|
expected: null,
|
|
location: {
|
|
start: { offset: 0, line: 1, column: 1 },
|
|
end: { offset: 1, line: 1, column: 2 }
|
|
}
|
|
});
|
|
});
|
|
|
|
it("allows to set custom location info", function() {
|
|
let parser = peg.generate([
|
|
'start = "a" {',
|
|
' error("a", {',
|
|
' start: { offset: 1, line: 1, column: 2 },',
|
|
' end: { offset: 2, line: 1, column: 3 }',
|
|
' });',
|
|
'}'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toFailToParse("a", {
|
|
message: "a",
|
|
expected: null,
|
|
found: null,
|
|
location: {
|
|
start: { offset: 1, line: 1, column: 2 },
|
|
end: { offset: 2, line: 1, column: 3 }
|
|
}
|
|
});
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("when the expression doesn't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = "a" { return 42; }', options);
|
|
|
|
expect(parser).toFailToParse("b");
|
|
});
|
|
|
|
it("doesn't execute the code", function() {
|
|
let parser = peg.generate(
|
|
'start = "a" { throw "Boom!"; } / "b"',
|
|
options
|
|
);
|
|
|
|
expect(parser).toParse("b");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("choice", function() {
|
|
describe("when any expression matches", function() {
|
|
it("returns its match result", function() {
|
|
let parser = peg.generate('start = "a" / "b" / "c"', options);
|
|
|
|
expect(parser).toParse("a", "a");
|
|
expect(parser).toParse("b", "b");
|
|
expect(parser).toParse("c", "c");
|
|
});
|
|
});
|
|
|
|
describe("when all expressions don't match", function() {
|
|
it("reports match failure", function() {
|
|
let parser = peg.generate('start = "a" / "b" / "c"', options);
|
|
|
|
expect(parser).toFailToParse("d");
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("error reporting", function() {
|
|
describe("behavior", function() {
|
|
it("reports only the rightmost error", function() {
|
|
let parser = peg.generate('start = "a" "b" / "a" "c" "d"', options);
|
|
|
|
expect(parser).toFailToParse("ace", {
|
|
expected: [{ type: "literal", text: "d", ignoreCase: false }]
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("expectations reporting", function() {
|
|
it("reports expectations correctly with no alternative", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("ab", {
|
|
expected: [{ type: "end" }]
|
|
});
|
|
});
|
|
|
|
it("reports expectations correctly with one alternative", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
expected: [{ type: "literal", text: "a", ignoreCase: false }]
|
|
});
|
|
});
|
|
|
|
it("reports expectations correctly with multiple alternatives", function() {
|
|
let parser = peg.generate('start = "a" / "b" / "c"', options);
|
|
|
|
expect(parser).toFailToParse("d", {
|
|
expected: [
|
|
{ type: "literal", text: "a", ignoreCase: false },
|
|
{ type: "literal", text: "b", ignoreCase: false },
|
|
{ type: "literal", text: "c", ignoreCase: false }
|
|
]
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("found string reporting", function() {
|
|
it("reports found string correctly at the end of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("", { found: null });
|
|
});
|
|
|
|
it("reports found string correctly in the middle of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", { found: "b" });
|
|
});
|
|
});
|
|
|
|
describe("message building", function() {
|
|
it("builds message correctly with no alternative", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("ab", {
|
|
message: 'Expected end of input but "b" found.'
|
|
});
|
|
});
|
|
|
|
it("builds message correctly with one alternative", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
message: 'Expected "a" but "b" found.'
|
|
});
|
|
});
|
|
|
|
it("builds message correctly with multiple alternatives", function() {
|
|
let parser = peg.generate('start = "a" / "b" / "c"', options);
|
|
|
|
expect(parser).toFailToParse("d", {
|
|
message: 'Expected "a", "b", or "c" but "d" found.'
|
|
});
|
|
});
|
|
|
|
it("builds message correctly at the end of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("", {
|
|
message: 'Expected "a" but end of input found.'
|
|
});
|
|
});
|
|
|
|
it("builds message correctly in the middle of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
message: 'Expected "a" but "b" found.'
|
|
});
|
|
});
|
|
|
|
it("removes duplicates from expectations", function() {
|
|
let parser = peg.generate('start = "a" / "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
message: 'Expected "a" but "b" found.'
|
|
});
|
|
});
|
|
|
|
it("sorts expectations", function() {
|
|
let parser = peg.generate('start = "c" / "b" / "a"', options);
|
|
|
|
expect(parser).toFailToParse("d", {
|
|
message: 'Expected "a", "b", or "c" but "d" found.'
|
|
});
|
|
});
|
|
|
|
});
|
|
|
|
describe("position reporting", function() {
|
|
it("reports position correctly at the end of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("", {
|
|
location: {
|
|
start: { offset: 0, line: 1, column: 1 },
|
|
end: { offset: 0, line: 1, column: 1 }
|
|
}
|
|
});
|
|
});
|
|
|
|
it("reports position correctly in the middle of input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("b", {
|
|
location: {
|
|
start: { offset: 0, line: 1, column: 1 },
|
|
end: { offset: 1, line: 1, column: 2 }
|
|
}
|
|
});
|
|
});
|
|
|
|
it("reports position correctly with trailing input", function() {
|
|
let parser = peg.generate('start = "a"', options);
|
|
|
|
expect(parser).toFailToParse("aa", {
|
|
location: {
|
|
start: { offset: 1, line: 1, column: 2 },
|
|
end: { offset: 2, line: 1, column: 3 }
|
|
}
|
|
});
|
|
});
|
|
|
|
it("reports position correctly in complex cases", function() {
|
|
let parser = peg.generate([
|
|
'start = line (nl+ line)*',
|
|
'line = digit (" "+ digit)*',
|
|
'digit = [0-9]',
|
|
'nl = "\\r"? "\\n"'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toFailToParse("1\n2\n\n3\n\n\n4 5 x", {
|
|
location: {
|
|
start: { offset: 13, line: 7, column: 5 },
|
|
end: { offset: 14, line: 7, column: 6 }
|
|
}
|
|
});
|
|
|
|
/* Newline representations */
|
|
expect(parser).toFailToParse("1\nx", { // Old Mac
|
|
location: {
|
|
start: { offset: 2, line: 2, column: 1 },
|
|
end: { offset: 3, line: 2, column: 2 }
|
|
}
|
|
});
|
|
expect(parser).toFailToParse("1\r\nx", { // Windows
|
|
location: {
|
|
start: { offset: 3, line: 2, column: 1 },
|
|
end: { offset: 4, line: 2, column: 2 }
|
|
}
|
|
});
|
|
});
|
|
});
|
|
});
|
|
|
|
/*
|
|
* Following examples are from Wikipedia, see
|
|
* http://en.wikipedia.org/w/index.php?title=Parsing_expression_grammar&oldid=335106938.
|
|
*/
|
|
describe("complex examples", function() {
|
|
it("handles arithmetics example correctly", function() {
|
|
/*
|
|
* Value ← [0-9]+ / '(' Expr ')'
|
|
* Product ← Value (('*' / '/') Value)*
|
|
* Sum ← Product (('+' / '-') Product)*
|
|
* Expr ← Sum
|
|
*/
|
|
let parser = peg.generate([
|
|
'Expr = Sum',
|
|
'Sum = head:Product tail:(("+" / "-") Product)* {',
|
|
' return tail.reduce(function(result, element) {',
|
|
' if (element[0] === "+") { return result + element[1]; }',
|
|
' if (element[0] === "-") { return result - element[1]; }',
|
|
' }, head);',
|
|
' }',
|
|
'Product = head:Value tail:(("*" / "/") Value)* {',
|
|
' return tail.reduce(function(result, element) {',
|
|
' if (element[0] === "*") { return result * element[1]; }',
|
|
' if (element[0] === "/") { return result / element[1]; }',
|
|
' }, head);',
|
|
' }',
|
|
'Value = digits:[0-9]+ { return parseInt(digits.join(""), 10); }',
|
|
' / "(" expr:Expr ")" { return expr; }'
|
|
].join("\n"), options);
|
|
|
|
/* The "value" rule */
|
|
expect(parser).toParse("0", 0);
|
|
expect(parser).toParse("123", 123);
|
|
expect(parser).toParse("(42+43)", 42+43);
|
|
|
|
/* The "product" rule */
|
|
expect(parser).toParse("42", 42);
|
|
expect(parser).toParse("42*43", 42*43);
|
|
expect(parser).toParse("42*43*44*45", 42*43*44*45);
|
|
expect(parser).toParse("42/43", 42/43);
|
|
expect(parser).toParse("42/43/44/45", 42/43/44/45);
|
|
|
|
/* The "sum" rule */
|
|
expect(parser).toParse("42*43", 42*43);
|
|
expect(parser).toParse("42*43+44*45", 42*43+44*45);
|
|
expect(parser).toParse("42*43+44*45+46*47+48*49", 42*43+44*45+46*47+48*49);
|
|
expect(parser).toParse("42*43-44*45", 42*43-44*45);
|
|
expect(parser).toParse("42*43-44*45-46*47-48*49", 42*43-44*45-46*47-48*49);
|
|
|
|
/* The "expr" rule */
|
|
expect(parser).toParse("42+43", 42+43);
|
|
|
|
/* Complex test */
|
|
expect(parser).toParse("(1+2)*(3+4)", (1+2)*(3+4));
|
|
});
|
|
|
|
it("handles non-context-free language correctly", function() {
|
|
/* The following parsing expression grammar describes the classic
|
|
* non-context-free language { a^n b^n c^n : n >= 1 }:
|
|
*
|
|
* S ← &(A c) a+ B !(a/b/c)
|
|
* A ← a A? b
|
|
* B ← b B? c
|
|
*/
|
|
let parser = peg.generate([
|
|
'S = &(A "c") a:"a"+ B:B !("a" / "b" / "c") { return a.join("") + B; }',
|
|
'A = a:"a" A:A? b:"b" { return [a, A, b].join(""); }',
|
|
'B = b:"b" B:B? c:"c" { return [b, B, c].join(""); }'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("abc", "abc");
|
|
expect(parser).toParse("aaabbbccc", "aaabbbccc");
|
|
expect(parser).toFailToParse("aabbbccc");
|
|
expect(parser).toFailToParse("aaaabbbccc");
|
|
expect(parser).toFailToParse("aaabbccc");
|
|
expect(parser).toFailToParse("aaabbbbccc");
|
|
expect(parser).toFailToParse("aaabbbcc");
|
|
expect(parser).toFailToParse("aaabbbcccc");
|
|
});
|
|
|
|
it("handles nested comments example correctly", function() {
|
|
/*
|
|
* Begin ← "(*"
|
|
* End ← "*)"
|
|
* C ← Begin N* End
|
|
* N ← C / (!Begin !End Z)
|
|
* Z ← any single character
|
|
*/
|
|
let parser = peg.generate([
|
|
'C = begin:Begin ns:N* end:End { return begin + ns.join("") + end; }',
|
|
'N = C',
|
|
' / !Begin !End z:Z { return z; }',
|
|
'Z = .',
|
|
'Begin = "(*"',
|
|
'End = "*)"'
|
|
].join("\n"), options);
|
|
|
|
expect(parser).toParse("(**)", "(**)");
|
|
expect(parser).toParse("(*abc*)", "(*abc*)");
|
|
expect(parser).toParse("(*(**)*)", "(*(**)*)");
|
|
expect(parser).toParse(
|
|
"(*abc(*def*)ghi(*(*(*jkl*)*)*)mno*)",
|
|
"(*abc(*def*)ghi(*(*(*jkl*)*)*)mno*)"
|
|
);
|
|
});
|
|
});
|
|
});
|
|
});
|