You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pegjs/test/api/plugin-api.spec.js

129 lines
3.4 KiB
JavaScript

"use strict";
let chai = require("chai");
let peg = require("../../lib/peg");
let expect = chai.expect;
describe("plugin API", function() {
describe("use", function() {
let grammar = "start = 'a'";
it("is called for each plugin", function() {
let pluginsUsed = [false, false, false];
let plugins = [
{ use() { pluginsUsed[0] = true; } },
{ use() { pluginsUsed[1] = true; } },
{ use() { pluginsUsed[2] = true; } }
];
peg.generate(grammar, { plugins: plugins });
expect(pluginsUsed).to.deep.equal([true, true, true]);
});
it("receives configuration", function() {
let plugin = {
use(config) {
expect(config).to.be.an("object");
expect(config.parser).to.be.an("object");
expect(config.parser.parse("start = 'a'")).to.be.an("object");
expect(config.passes).to.be.an("object");
expect(config.passes.check).to.be.an("array");
config.passes.check.forEach(pass => {
expect(pass).to.be.a("function");
});
expect(config.passes.transform).to.be.an("array");
config.passes.transform.forEach(pass => {
expect(pass).to.be.a("function");
});
expect(config.passes.generate).to.be.an("array");
config.passes.generate.forEach(pass => {
expect(pass).to.be.a("function");
});
}
};
peg.generate(grammar, { plugins: [plugin] });
});
it("receives options", function() {
let plugin = {
use(config, options) {
expect(options).to.equal(generateOptions);
}
};
let generateOptions = { plugins: [plugin], foo: 42 };
peg.generate(grammar, generateOptions);
});
it("can replace parser", function() {
let plugin = {
use(config) {
let parser = peg.generate([
"start = .* {",
" return {",
" type: 'grammar',",
" rules: [",
" {",
" type: 'rule',",
" name: 'start',",
" expression: { type: 'literal', value: text(), ignoreCase: false }",
" }",
" ]",
" };",
"}"
].join("\n"));
config.parser = parser;
}
};
let parser = peg.generate("a", { plugins: [plugin] });
expect(parser.parse("a")).to.equal("a");
});
it("can change compiler passes", function() {
let plugin = {
use(config) {
function pass(ast) {
ast.code = "({ parse: function() { return 42; } })";
}
config.passes.generate = [pass];
}
};
let parser = peg.generate(grammar, { plugins: [plugin] });
expect(parser.parse("a")).to.equal(42);
});
it("can change options", function() {
let grammar = [
"a = 'x'",
"b = 'x'",
"c = 'x'"
].join("\n");
let plugin = {
use(config, options) {
options.allowedStartRules = ["b", "c"];
}
};
let parser = peg.generate(grammar, {
allowedStartRules: ["a"],
plugins: [plugin]
});
expect(() => { parser.parse("x", { startRule: "a" }); }).to.throw();
expect(parser.parse("x", { startRule: "b" })).to.equal("x");
expect(parser.parse("x", { startRule: "c" })).to.equal("x");
});
});
});