cerxes/babel
3
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Deopt evaluation of undefined with a local binding. Fix #5204 (#5206)

Browse Source
This commit is contained in:
Boopathi Rajaa 2017-02-08 16:37:14 +01:00 committed by Henry Zhu
parent 5c5262437e
commit f8ffe03e79
2 changed files with 21 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
packages/babel-traverse/src/path/evaluation.js
View File

@ -176,11 +176,11 @@ export function evaluate(): { confident: boolean; value: any } {
return binding.value; return binding.value;
} else { } else {
if (node.name === "undefined") { if (node.name === "undefined") {
return undefined; return binding ? deopt(binding.path) : undefined;
} else if (node.name === "Infinity") { } else if (node.name === "Infinity") {
return Infinity; return binding ? deopt(binding.path) : Infinity;
} else if (node.name === "NaN") { } else if (node.name === "NaN") {
return NaN; return binding ? deopt(binding.path) : NaN;
} }
const resolved = path.resolve(); const resolved = path.resolve();

18
packages/babel-traverse/test/evaluation.js
View File

@ -101,4 +101,22 @@ describe("evaluation", function () {
false false
); );
}); });
it("should evaluate undefined, NaN and Infinity", () => {
assert.strictEqual(getPath("undefined").get("body.0.expression").evaluate().confident, true);
assert.strictEqual(getPath("NaN").get("body.0.expression").evaluate().confident, true);
assert.strictEqual(getPath("Infinity").get("body.0.expression").evaluate().confident, true);
});
it("should deopt redefined primitives - undefined, NaN and Infinity", () => {
const eval_undef = getPath("let undefined; undefined;").get("body.1.expression").evaluate();
const eval_nan = getPath("let NaN; NaN;").get("body.1.expression").evaluate();
const eval_inf = getPath("let Infinity; Infinity;").get("body.1.expression").evaluate();
assert.strictEqual(eval_undef.confident, false);
assert.strictEqual(eval_nan.confident, false);
assert.strictEqual(eval_inf.confident, false);
assert.strictEqual(eval_undef.deopt.type, "VariableDeclarator");
assert.strictEqual(eval_undef.deopt.parentPath.node.kind, "let");
});
}); });