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Specs cleanup: Implement PEG.js API specs

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Some parts were previously part of generated parser specs, these were
moved.
redux
David Majda 10 years ago
parent 0306a76152
commit d0ff834a3d
3 changed files with 168 additions and 65 deletions
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65
spec/api/generated-parser.spec.js
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@ -1024,71 +1024,6 @@ describe("generated parser", function() {
});
});
describe("allowed start rules", function() {
var grammar = [
'a = "x"',
'b = "x"',
'c = "x"'
].join("\n");
describe("without the |allowedStartRules| option", function() {
var parser = PEG.buildParser(grammar);
it("allows the first rule", function() {
expect(parser).toParse("x", { startRule: "a" }, "x");
});
it("does not allow any other rules", function() {
expect(parser).toFailToParse("x", { startRule: "b" }, { });
expect(parser).toFailToParse("x", { startRule: "c" }, { });
});
});
describe("with the |allowedStartRules| option", function() {
var parser = PEG.buildParser(grammar, { allowedStartRules: ["b", "c"] });
it("allows the specified rules", function() {
expect(parser).toParse("x", { startRule: "b" }, "x");
expect(parser).toParse("x", { startRule: "c" }, "x");
});
it("does not allow any other rules", function() {
expect(parser).toFailToParse("x", { startRule: "a" }, { });
});
});
});
describe("output", function() {
var grammar = 'start = "a"';
describe("without the |output| option", function() {
it("returns a parser object", function() {
var parser = PEG.buildParser(grammar);
expect(typeof parser).toBe("object");
expect(parser).toParse("a", "a");
});
});
describe("when the |output| option is set to \"parser\"", function() {
it("returns a parser object", function() {
var parser = PEG.buildParser(grammar, { output: "parser" });
expect(typeof parser).toBe("object");
expect(parser).toParse("a", "a");
});
});
describe("when the |output| option is set to \"source\"", function() {
it("returns a parser source code", function() {
var source = PEG.buildParser(grammar, { output: "source" });
expect(typeof source).toBe("string");
expect(eval(source)).toParse("a", "a");
});
});
});
/*
* Following examples are from Wikipedia, see
* http://en.wikipedia.org/w/index.php?title=Parsing_expression_grammar&oldid=335106938.

167
spec/api/pegjs-api.spec.js
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@ -0,0 +1,167 @@
describe("PEG.js API", function() {
describe("buildParser", function() {
it("builds parsers", function() {
var parser = PEG.buildParser('start = "a"');
expect(typeof parser).toBe("object");
expect(parser.parse("a")).toBe("a");
});
it("throws an exception on syntax error", function() {
expect(function() { PEG.buildParser('start = @'); }).toThrow();
});
it("throws an exception on semantic error", function() {
expect(function() { PEG.buildParser('start = missing'); }).toThrow();
});
describe("allowed start rules", function() {
var grammar = [
'a = "x"',
'b = "x"',
'c = "x"'
].join("\n");
/*
* The |allowedStartRules| option is implemented separately for each
* optimization mode, so we need to test it in both.
*/
describe("when optimizing for parsing speed", function() {
describe("when |allowedStartRules| is not set", function() {
it("the generated parser can start only from the first rule", function() {
var parser = PEG.buildParser(grammar, { optimize: "speed" });
expect(parser.parse("x", { startRule: "a" })).toBe("x");
expect(
function() { parser.parse("x", { startRule: "b" }); }
).toThrow();
expect(
function() { parser.parse("x", { startRule: "c" }); }
).toThrow();
});
});
describe("when |allowedStartRules| is set", function() {
it("the generated parser can start only from specified rules", function() {
var parser = PEG.buildParser(grammar, {
optimize: "speed",
allowedStartRules: ["b", "c"]
});
expect(
function() { parser.parse("x", { startRule: "a" }); }
).toThrow();
expect(parser.parse("x", { startRule: "b" })).toBe("x");
expect(parser.parse("x", { startRule: "c" })).toBe("x");
});
});
});
describe("when optimizing for code size", function() {
describe("when |allowedStartRules| is not set", function() {
it("the generated parser can start only from the first rule", function() {
var parser = PEG.buildParser(grammar, { optimize: "size" });
expect(parser.parse("x", { startRule: "a" })).toBe("x");
expect(
function() { parser.parse("x", { startRule: "b" }); }
).toThrow();
expect(
function() { parser.parse("x", { startRule: "c" }); }
).toThrow();
});
});
describe("when |allowedStartRules| is set", function() {
it("the generated parser can start only from specified rules", function() {
var parser = PEG.buildParser(grammar, {
optimize: "size",
allowedStartRules: ["b", "c"]
});
expect(
function() { parser.parse("x", { startRule: "a" }); }
).toThrow();
expect(parser.parse("x", { startRule: "b" })).toBe("x");
expect(parser.parse("x", { startRule: "c" })).toBe("x");
});
});
});
});
describe("intermediate results caching", function() {
var grammar = [
'{ var n = 0; }',
'start = (a "b") / (a "c") { return n; }',
'a = "a" { n++; }'
].join("\n");
describe("when |cache| is not set", function() {
it("the generated parser doesn't cache intermediate parse results", function() {
var parser = PEG.buildParser(grammar);
expect(parser.parse("ac")).toBe(2);
});
});
describe("when |cache| is set to |false|", function() {
it("the generated parser doesn't cache intermediate parse results", function() {
var parser = PEG.buildParser(grammar, { cache: false });
expect(parser.parse("ac")).toBe(2);
});
});
describe("when |cache| is set to |true|", function() {
it("the generated parser caches intermediate parse results", function() {
var parser = PEG.buildParser(grammar, { cache: true });
expect(parser.parse("ac")).toBe(1);
});
});
});
/*
* The |optimize| option isn't tested because there is no meaningful way to
* write the specs without turning this into a performance test.
*/
describe("output", function() {
var grammar = 'start = "a"';
describe("when |output| is not set", function() {
it("defaults to \"parser\"", function() {
var parser = PEG.buildParser(grammar);
expect(typeof parser).toBe("object");
expect(parser.parse("a")).toBe("a");
});
});
describe("when |output| is set to |\"parser\"|", function() {
it("returns generated parser object", function() {
var parser = PEG.buildParser(grammar, { output: "parser" });
expect(typeof parser).toBe("object");
expect(parser.parse("a")).toBe("a");
});
});
describe("when |output| is set to |\"source\"|", function() {
it("returns generated parser source code", function() {
var source = PEG.buildParser(grammar, { output: "source" });
expect(typeof source).toBe("string");
expect(eval(source).parse("a")).toBe("a");
});
});
});
/* The |plugins| option is tested in plugin API specs. */
it("accepts custom options", function() {
PEG.buildParser('start = "a"', { foo: 42 });
});
});
});

1
spec/index.html
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@ -13,6 +13,7 @@
<script src="unit/compiler/passes/report-left-recursion.spec.js"></script>
<script src="unit/compiler/passes/remove-proxy-rules.spec.js"></script>
<script src="unit/compiler/passes/generate-bytecode.spec.js"></script>
<script src="api/pegjs-api.spec.js"></script>
<script src="api/generated-parser.spec.js"></script>
<script>
(function() {

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