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pegjs/spec/compiler/passes/report-left-recursion.spec.js

89 lines
2.7 KiB
JavaScript

describe("compiler pass |reportLeftRecursion|", function() {
var pass = PEG.compiler.passes.reportLeftRecursion;
beforeEach(function() {
this.addMatchers({
toReportLeftRecursionIn: function(grammar) {
var ast = PEG.parser.parse(grammar);
try {
this.actual(ast);
this.message = function() {
return "Expected the pass to report left recursion for grammar "
+ jasmine.pp(grammar) + ", "
+ "but it didn't.";
};
return false;
} catch (e) {
if (this.isNot) {
this.message = function() {
return "Expected the pass not to report left recursion for grammar "
+ jasmine.pp(grammar) + ", "
+ "but it did.";
};
} else {
this.message = function() {
return "Expected the pass to report left recursion for grammar "
+ jasmine.pp(grammar) + ", "
+ "but it reported an error with message "
+ jasmine.pp(e.message) + ".";
};
}
return e.message === 'Left recursion detected for rule \"start\".';
}
}
});
});
it("reports left recursion inside a rule", function() {
expect(pass).toReportLeftRecursionIn('start = start');
});
it("reports left recursion inside a choice", function() {
expect(pass).toReportLeftRecursionIn('start = start / "a" / "b"');
expect(pass).toReportLeftRecursionIn('start = "a" / "b" / start');
});
it("reports left recursion inside a sequence", function() {
expect(pass).toReportLeftRecursionIn('start = start "a" "b"');
});
it("reports left recursion inside a labeled", function() {
expect(pass).toReportLeftRecursionIn('start = label:start');
});
it("reports left recursion inside a simple and", function() {
expect(pass).toReportLeftRecursionIn('start = &start');
});
it("reports left recursion inside a simple not", function() {
expect(pass).toReportLeftRecursionIn('start = &start');
});
it("reports left recursion inside an optional", function() {
expect(pass).toReportLeftRecursionIn('start = start?');
});
it("reports left recursion inside a zero or more", function() {
expect(pass).toReportLeftRecursionIn('start = start*');
});
it("reports left recursion inside a one or more", function() {
expect(pass).toReportLeftRecursionIn('start = start+');
});
it("reports left recursion inside an action", function() {
expect(pass).toReportLeftRecursionIn('start = start { }');
});
it("reports indirect left recursion", function() {
expect(pass).toReportLeftRecursionIn([
'start = stop',
'stop = start'
].join("\n"));
});
});