57 lines
1.8 KiB
JavaScript

let traverse = require("../lib").default;
let assert = require("assert");
let parse = require("babylon").parse;
function getPath(code) {
let ast = parse(code);
let path;
traverse(ast, {
Program: function (_path) {
path = _path;
_path.stop();
}
});
return path;
}
suite("inference", function () {
suite("baseTypeStrictlyMatches", function () {
test("it should work with null", function () {
let path = getPath("var x = null; x === null").get("body")[1].get("expression");
let left = path.get("left");
let right = path.get("right");
let strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(strictMatch, "null should be equal to null");
});
test("it should work with numbers", function () {
let path = getPath("var x = 1; x === 2").get("body")[1].get("expression");
let left = path.get("left");
let right = path.get("right");
let strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(strictMatch, "null should be equal to null");
});
test("it should bail when type changes", function () {
let path = getPath("var x = 1; if (foo) x = null;else x = 3; x === 2").get("body")[2].get("expression");
let left = path.get("left");
let right = path.get("right");
let strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(!strictMatch, "type might change in if statement");
});
test("it should differentiate between null and undefined", function () {
let path = getPath("var x; x === null").get("body")[1].get("expression");
let left = path.get("left");
let right = path.get("right");
let strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(!strictMatch, "null should not match undefined");
});
});
});