1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/tests/ecma_6/Generators/syntax.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,97 @@
1.4 +// This file was written by Andy Wingo <wingo@igalia.com> and originally
1.5 +// contributed to V8 as generators-parsing.js, available here:
1.6 +//
1.7 +// http://code.google.com/p/v8/source/browse/branches/bleeding_edge/test/mjsunit/harmony/generators-parsing.js
1.8 +
1.9 +function assertSyntaxError(str) {
1.10 + var msg;
1.11 + var evil = eval;
1.12 + try {
1.13 + // Non-direct eval.
1.14 + evil(str);
1.15 + } catch (exc) {
1.16 + if (exc instanceof SyntaxError)
1.17 + return;
1.18 + msg = "Assertion failed: expected SyntaxError, got " + exc;
1.19 + }
1.20 + if (msg === undefined)
1.21 + msg = "Assertion failed: expected SyntaxError, but no exception thrown";
1.22 + throw new Error(msg + " - " + str);
1.23 +}
1.24 +
1.25 +// Yield statements.
1.26 +function* g() { yield 3; yield 4; }
1.27 +
1.28 +// Yield expressions.
1.29 +function* g() { (yield 3) + (yield 4); }
1.30 +
1.31 +// You can have a generator in strict mode.
1.32 +function* g() { "use strict"; yield 3; yield 4; }
1.33 +
1.34 +// Generators can have return statements also, which internally parse to a kind
1.35 +// of yield expression.
1.36 +function* g() { yield 1; return; }
1.37 +function* g() { yield 1; return 2; }
1.38 +function* g() { yield 1; return 2; yield "dead"; }
1.39 +
1.40 +// Generator expression.
1.41 +(function* () { yield 3; });
1.42 +
1.43 +// Named generator expression.
1.44 +(function* g() { yield 3; });
1.45 +
1.46 +// Generators do not have to contain yield expressions.
1.47 +function* g() { }
1.48 +
1.49 +// YieldExpressions can occur in the RHS of a YieldExpression.
1.50 +function* g() { yield yield 1; }
1.51 +function* g() { yield 3 + (yield 4); }
1.52 +
1.53 +// Generator definitions with a name of "yield" are not specifically ruled out
1.54 +// by the spec, as the `yield' name is outside the generator itself. However,
1.55 +// in strict-mode, "yield" is an invalid identifier.
1.56 +function* yield() { (yield 3) + (yield 4); }
1.57 +assertSyntaxError("function* yield() { 'use strict'; (yield 3) + (yield 4); }");
1.58 +
1.59 +// In classic mode, yield is a normal identifier, outside of generators.
1.60 +function yield(yield) { yield: yield (yield + yield (0)); }
1.61 +
1.62 +// Yield is always valid as a key in an object literal.
1.63 +({ yield: 1 });
1.64 +function* g() { yield ({ yield: 1 }) }
1.65 +function* g() { yield ({ get yield() { return 1; }}) }
1.66 +
1.67 +// Yield is a valid property name.
1.68 +function* g(obj) { yield obj.yield; }
1.69 +
1.70 +// Checks that yield is a valid label in classic mode, but not valid in a strict
1.71 +// mode or in generators.
1.72 +function f() { yield: 1 }
1.73 +assertSyntaxError("function f() { 'use strict'; yield: 1 }")
1.74 +assertSyntaxError("function* g() { yield: 1 }")
1.75 +
1.76 +// Yield is only a keyword in the body of the generator, not in nested
1.77 +// functions.
1.78 +function* g() { function f(yield) { yield (yield + yield (0)); } }
1.79 +
1.80 +// Yield needs a RHS.
1.81 +assertSyntaxError("function* g() { yield; }");
1.82 +
1.83 +// Yield in a generator is not an identifier.
1.84 +assertSyntaxError("function* g() { yield = 10; }");
1.85 +
1.86 +// Yield binds very loosely, so this parses as "yield (3 + yield 4)", which is
1.87 +// invalid.
1.88 +assertSyntaxError("function* g() { yield 3 + yield 4; }");
1.89 +
1.90 +// Yield is still a future-reserved-word in strict mode
1.91 +assertSyntaxError("function f() { 'use strict'; var yield = 13; }");
1.92 +
1.93 +// The name of the NFE is let-bound in G, so is invalid.
1.94 +assertSyntaxError("function* g() { yield (function yield() {}); }");
1.95 +
1.96 +// In generators, yield is invalid as a formal argument name.
1.97 +assertSyntaxError("function* g(yield) { yield (10); }");
1.98 +
1.99 +if (typeof reportCompare == "function")
1.100 + reportCompare(true, true);
