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122 lines
4.1 KiB
JavaScript
122 lines
4.1 KiB
JavaScript
"use strict";
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let chai = require("chai");
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let helpers = require("./helpers");
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let peg = require("../../../../lib/peg");
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chai.use(helpers);
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let expect = chai.expect;
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describe("compiler pass |reportInfiniteRecursion|", function() {
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let pass = peg.compiler.passes.check.reportInfiniteRecursion;
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it("reports direct left recursion", function() {
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expect(pass).to.reportError("start = start", {
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message: "Possible infinite loop when parsing (left recursion: start -> start).",
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location: {
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start: { offset: 8, line: 1, column: 9 },
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end: { offset: 13, line: 1, column: 14 }
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}
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});
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});
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it("reports indirect left recursion", function() {
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expect(pass).to.reportError([
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"start = stop",
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"stop = start"
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].join("\n"), {
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message: "Possible infinite loop when parsing (left recursion: start -> stop -> start).",
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location: {
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start: { offset: 20, line: 2, column: 8 },
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end: { offset: 25, line: 2, column: 13 }
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}
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});
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});
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describe("in sequences", function() {
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it("reports left recursion if all preceding elements match empty string", function() {
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expect(pass).to.reportError("start = '' '' '' start");
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});
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it("doesn't report left recursion if some preceding element doesn't match empty string", function() {
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expect(pass).to.not.reportError("start = 'a' '' '' start");
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expect(pass).to.not.reportError("start = '' 'a' '' start");
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expect(pass).to.not.reportError("start = '' '' 'a' start");
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});
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// Regression test for #359.
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it("reports left recursion when rule reference is wrapped in an expression", function() {
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expect(pass).to.reportError("start = '' start?");
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});
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it("computes expressions that always consume input on success correctly", function() {
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expect(pass).to.reportError([
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"start = a start",
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"a 'a' = ''"
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].join("\n"));
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expect(pass).to.not.reportError([
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"start = a start",
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"a 'a' = 'a'"
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].join("\n"));
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expect(pass).to.reportError("start = ('' / 'a' / 'b') start");
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expect(pass).to.reportError("start = ('a' / '' / 'b') start");
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expect(pass).to.reportError("start = ('a' / 'b' / '') start");
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expect(pass).to.not.reportError("start = ('a' / 'b' / 'c') start");
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expect(pass).to.reportError("start = ('' { }) start");
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expect(pass).to.not.reportError("start = ('a' { }) start");
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expect(pass).to.reportError("start = ('' '' '') start");
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expect(pass).to.not.reportError("start = ('a' '' '') start");
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expect(pass).to.not.reportError("start = ('' 'a' '') start");
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expect(pass).to.not.reportError("start = ('' '' 'a') start");
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expect(pass).to.reportError("start = a:'' start");
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expect(pass).to.not.reportError("start = a:'a' start");
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expect(pass).to.reportError("start = $'' start");
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expect(pass).to.not.reportError("start = $'a' start");
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expect(pass).to.reportError("start = &'' start");
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expect(pass).to.reportError("start = &'a' start");
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expect(pass).to.reportError("start = !'' start");
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expect(pass).to.reportError("start = !'a' start");
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expect(pass).to.reportError("start = ''? start");
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expect(pass).to.reportError("start = 'a'? start");
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expect(pass).to.reportError("start = ''* start");
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expect(pass).to.reportError("start = 'a'* start");
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expect(pass).to.reportError("start = ''+ start");
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expect(pass).to.not.reportError("start = 'a'+ start");
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expect(pass).to.reportError("start = ('') start");
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expect(pass).to.not.reportError("start = ('a') start");
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expect(pass).to.reportError("start = &{ } start");
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expect(pass).to.reportError("start = !{ } start");
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expect(pass).to.reportError([
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"start = a start",
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"a = ''"
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].join("\n"));
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expect(pass).to.not.reportError([
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"start = a start",
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"a = 'a'"
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].join("\n"));
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expect(pass).to.reportError("start = '' start");
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expect(pass).to.not.reportError("start = 'a' start");
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expect(pass).to.not.reportError("start = [a-d] start");
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expect(pass).to.not.reportError("start = . start");
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});
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});
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});
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