392 lines
13 KiB
JavaScript

import traverse from "../lib";
import assert from "assert";
import { parse } from "babylon";
import * as t from "@babel/types";
function getPath(code) {
const ast = parse(code, { plugins: ["flow", "asyncGenerators"] });
let path;
traverse(ast, {
Program: function(_path) {
path = _path;
_path.stop();
},
});
return path;
}
describe("inference", function() {
describe("baseTypeStrictlyMatches", function() {
it("it should work with null", function() {
const path = getPath("var x = null; x === null")
.get("body")[1]
.get("expression");
const left = path.get("left");
const right = path.get("right");
const strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(strictMatch, "null should be equal to null");
});
it("it should work with numbers", function() {
const path = getPath("var x = 1; x === 2")
.get("body")[1]
.get("expression");
const left = path.get("left");
const right = path.get("right");
const strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(strictMatch, "number should be equal to number");
});
it("it should bail when type changes", function() {
const path = getPath("var x = 1; if (foo) x = null;else x = 3; x === 2")
.get("body")[2]
.get("expression");
const left = path.get("left");
const right = path.get("right");
const strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(!strictMatch, "type might change in if statement");
});
it("it should differentiate between null and undefined", function() {
const path = getPath("var x; x === null")
.get("body")[1]
.get("expression");
const left = path.get("left");
const right = path.get("right");
const strictMatch = left.baseTypeStrictlyMatches(right);
assert.ok(!strictMatch, "null should not match undefined");
});
});
describe("getTypeAnnotation", function() {
it("should infer from type cast", function() {
const path = getPath("(x: number)")
.get("body")[0]
.get("expression");
assert.ok(
t.isNumberTypeAnnotation(path.getTypeAnnotation()),
"should be number",
);
});
it("should infer string from template literal", function() {
const path = getPath("`hey`")
.get("body")[0]
.get("expression");
assert.ok(
t.isStringTypeAnnotation(path.getTypeAnnotation()),
"should be string",
);
});
it("should infer number from +x", function() {
const path = getPath("+x")
.get("body")[0]
.get("expression");
assert.ok(
t.isNumberTypeAnnotation(path.getTypeAnnotation()),
"should be number",
);
});
it("should infer T from new T", function() {
const path = getPath("new T")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "T",
"should be T",
);
});
it("should infer number from ++x", function() {
const path = getPath("++x")
.get("body")[0]
.get("expression");
assert.ok(
t.isNumberTypeAnnotation(path.getTypeAnnotation()),
"should be number",
);
});
it("should infer number from --x", function() {
const path = getPath("--x")
.get("body")[0]
.get("expression");
assert.ok(
t.isNumberTypeAnnotation(path.getTypeAnnotation()),
"should be number",
);
});
it("should infer void from void x", function() {
const path = getPath("void x")
.get("body")[0]
.get("expression");
assert.ok(
t.isVoidTypeAnnotation(path.getTypeAnnotation()),
"should be void",
);
});
it("should infer string from typeof x", function() {
const path = getPath("typeof x")
.get("body")[0]
.get("expression");
assert.ok(
t.isStringTypeAnnotation(path.getTypeAnnotation()),
"should be string",
);
});
it("should infer boolean from !x", function() {
const path = getPath("!x")
.get("body")[0]
.get("expression");
assert.ok(
t.isBooleanTypeAnnotation(path.getTypeAnnotation()),
"should be boolean",
);
});
it("should infer type of sequence expression", function() {
const path = getPath("a,1")
.get("body")[0]
.get("expression");
assert.ok(
t.isNumberTypeAnnotation(path.getTypeAnnotation()),
"should be number",
);
});
it("should infer type of logical expression", function() {
const path = getPath("'a' && 1")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isUnionTypeAnnotation(type), "should be a union");
assert.ok(
t.isStringTypeAnnotation(type.types[0]),
"first type in union should be string",
);
assert.ok(
t.isNumberTypeAnnotation(type.types[1]),
"second type in union should be number",
);
});
it("should infer type of conditional expression", function() {
const path = getPath("q ? true : 0")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isUnionTypeAnnotation(type), "should be a union");
assert.ok(
t.isBooleanTypeAnnotation(type.types[0]),
"first type in union should be boolean",
);
assert.ok(
t.isNumberTypeAnnotation(type.types[1]),
"second type in union should be number",
);
});
it("should infer RegExp from RegExp literal", function() {
const path = getPath("/.+/")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "RegExp",
"should be RegExp",
);
});
it("should infer Object from object expression", function() {
const path = getPath("({ a: 5 })")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "Object",
"should be Object",
);
});
it("should infer Array from array expression", function() {
const path = getPath("[ 5 ]")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "Array",
"should be Array",
);
});
it("should infer Function from function", function() {
const path = getPath("(function (): string {})")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "Function",
"should be Function",
);
});
it("should infer call return type using function", function() {
const path = getPath("(function (): string {})()")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isStringTypeAnnotation(type), "should be string");
});
it("should infer call return type using async function", function() {
const path = getPath("(async function (): string {})()")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "Promise",
"should be Promise",
);
});
it("should infer call return type using async generator function", function() {
const path = getPath("(async function * (): string {})()")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "AsyncIterator",
"should be AsyncIterator",
);
});
it("should infer number from x/y", function() {
const path = getPath("x/y")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be number");
});
it("should infer boolean from x instanceof y", function() {
const path = getPath("x instanceof y")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isBooleanTypeAnnotation(type), "should be boolean");
});
it("should infer number from 1 + 2", function() {
const path = getPath("1 + 2")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be number");
});
it("should infer string|number from x + y", function() {
const path = getPath("x + y")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(t.isUnionTypeAnnotation(type), "should be a union");
assert.ok(
t.isStringTypeAnnotation(type.types[0]),
"first type in union should be string",
);
assert.ok(
t.isNumberTypeAnnotation(type.types[1]),
"second type in union should be number",
);
});
it("should infer type of tagged template literal", function() {
const path = getPath("(function (): RegExp {}) `hey`")
.get("body")[0]
.get("expression");
const type = path.getTypeAnnotation();
assert.ok(
t.isGenericTypeAnnotation(type) && type.id.name === "RegExp",
"should be RegExp",
);
});
it("should infer constant identifier", function() {
const path = getPath("const x = 0; x").get("body.1.expression");
const type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be number");
});
it("should infer indirect constant identifier", function() {
const path = getPath("const x = 0; const y = x; y").get(
"body.2.expression",
);
const type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be number");
});
it("should infer identifier type from if statement (===)", function() {
const path = getPath(
`function test(x) {
if (x === true) x;
}`,
).get("body.0.body.body.0.consequent.expression");
const type = path.getTypeAnnotation();
assert.ok(t.isBooleanTypeAnnotation(type), "should be boolean");
});
it("should infer identifier type from if statement (typeof)", function() {
let path = getPath(
`function test(x) {
if (typeof x == 'string') x;
}`,
).get("body.0.body.body.0.consequent.expression");
let type = path.getTypeAnnotation();
assert.ok(t.isStringTypeAnnotation(type), "should be string");
path = getPath(
`function test(x) {
if (typeof x === 'number') x;
}`,
).get("body.0.body.body.0.consequent.expression");
type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be string");
});
it("should infer identifier type from if statement (&&)", function() {
let path = getPath(
`function test(x) {
if (typeof x == 'string' && x === 3) x;
}`,
).get("body.0.body.body.0.consequent.expression");
let type = path.getTypeAnnotation();
assert.ok(t.isUnionTypeAnnotation(type), "should be a union");
assert.ok(
t.isStringTypeAnnotation(type.types[0]),
"first type in union should be string",
);
assert.ok(
t.isNumberTypeAnnotation(type.types[1]),
"second type in union should be number",
);
path = getPath(
`function test(x) {
if (true && x === 3) x;
}`,
).get("body.0.body.body.0.consequent.expression");
type = path.getTypeAnnotation();
assert.ok(t.isNumberTypeAnnotation(type), "should be number");
path = getPath(
`function test(x) {
if (x === 'test' && true) x;
}`,
).get("body.0.body.body.0.consequent.expression");
type = path.getTypeAnnotation();
assert.ok(t.isStringTypeAnnotation(type), "should be string");
});
it("should infer identifier type from if statement (||)", function() {
const path = getPath(
`function test(x) {
if (typeof x == 'string' || x === 3) x;
}`,
).get("body.0.body.body.0.consequent.expression");
const type = path.getTypeAnnotation();
assert.ok(t.isAnyTypeAnnotation(type), "should be a any type");
});
it("should not infer identifier type from incorrect binding", function() {
const path = getPath(
`function outer(x) {
if (x === 3) {
function inner(x) {
x;
}
}
}`,
).get("body.0.body.body.0.consequent.body.0.body.body.0.expression");
const type = path.getTypeAnnotation();
assert.ok(t.isAnyTypeAnnotation(type), "should be a any type");
});
});
});