infer number index signature in JS object literals (#26221)

Fixes: #26208

Author: ajafff

src/compiler/checker.ts

@@ -16836,7 +16836,7 @@ namespace ts {
 
             function createObjectLiteralType() {
                 const stringIndexInfo = hasComputedStringProperty ? getObjectLiteralIndexInfo(node.properties, offset, propertiesArray, IndexKind.String) : undefined;
-                const numberIndexInfo = hasComputedNumberProperty && !isJSObjectLiteral ? getObjectLiteralIndexInfo(node.properties, offset, propertiesArray, IndexKind.Number) : undefined;
+                const numberIndexInfo = hasComputedNumberProperty ? getObjectLiteralIndexInfo(node.properties, offset, propertiesArray, IndexKind.Number) : undefined;
                 const result = createAnonymousType(node.symbol, propertiesTable, emptyArray, emptyArray, stringIndexInfo, numberIndexInfo);
                 const freshObjectLiteralFlag = compilerOptions.suppressExcessPropertyErrors ? 0 : TypeFlags.FreshLiteral;
                 result.flags |= TypeFlags.ContainsObjectLiteral | freshObjectLiteralFlag | (typeFlags & TypeFlags.PropagatingFlags);

tests/baselines/reference/checkJsObjectLiteralIndexSignatures.js

@@ -0,0 +1,23 @@
+//// [file.js]
+// @ts-check
+
+let n = Math.random();
+let s = `${n}`;
+
+const numericIndex = { [n]: 1 };
+numericIndex[n].toFixed();
+
+const stringIndex = { [s]: 1 };
+stringIndex[s].toFixed();
+
+
+
+//// [file.js]
+// @ts-check
+var _a, _b;
+var n = Math.random();
+var s = "" + n;
+var numericIndex = (_a = {}, _a[n] = 1, _a);
+numericIndex[n].toFixed();
+var stringIndex = (_b = {}, _b[s] = 1, _b);
+stringIndex[s].toFixed();

tests/baselines/reference/checkJsObjectLiteralIndexSignatures.symbols

@@ -0,0 +1,36 @@
+=== tests/cases/compiler/file.js ===
+// @ts-check
+
+let n = Math.random();
+>n : Symbol(n, Decl(file.js, 2, 3))
+>Math.random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+>Math : Symbol(Math, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>random : Symbol(Math.random, Decl(lib.es5.d.ts, --, --))
+
+let s = `${n}`;
+>s : Symbol(s, Decl(file.js, 3, 3))
+>n : Symbol(n, Decl(file.js, 2, 3))
+
+const numericIndex = { [n]: 1 };
+>numericIndex : Symbol(numericIndex, Decl(file.js, 5, 5))
+>[n] : Symbol([n], Decl(file.js, 5, 22))
+>n : Symbol(n, Decl(file.js, 2, 3))
+
+numericIndex[n].toFixed();
+>numericIndex[n].toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --))
+>numericIndex : Symbol(numericIndex, Decl(file.js, 5, 5))
+>n : Symbol(n, Decl(file.js, 2, 3))
+>toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --))
+
+const stringIndex = { [s]: 1 };
+>stringIndex : Symbol(stringIndex, Decl(file.js, 8, 5))
+>[s] : Symbol([s], Decl(file.js, 8, 21))
+>s : Symbol(s, Decl(file.js, 3, 3))
+
+stringIndex[s].toFixed();
+>stringIndex[s].toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --))
+>stringIndex : Symbol(stringIndex, Decl(file.js, 8, 5))
+>s : Symbol(s, Decl(file.js, 3, 3))
+>toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --))
+
+

tests/baselines/reference/checkJsObjectLiteralIndexSignatures.types

@@ -0,0 +1,46 @@
+=== tests/cases/compiler/file.js ===
+// @ts-check
+
+let n = Math.random();
+>n : number
+>Math.random() : number
+>Math.random : () => number
+>Math : Math
+>random : () => number
+
+let s = `${n}`;
+>s : string
+>`${n}` : string
+>n : number
+
+const numericIndex = { [n]: 1 };
+>numericIndex : { [x: number]: number; }
+>{ [n]: 1 } : { [x: number]: number; }
+>[n] : number
+>n : number
+>1 : 1
+
+numericIndex[n].toFixed();
+>numericIndex[n].toFixed() : string
+>numericIndex[n].toFixed : (fractionDigits?: number) => string
+>numericIndex[n] : number
+>numericIndex : { [x: number]: number; }
+>n : number
+>toFixed : (fractionDigits?: number) => string
+
+const stringIndex = { [s]: 1 };
+>stringIndex : { [x: string]: number; }
+>{ [s]: 1 } : { [x: string]: number; }
+>[s] : number
+>s : string
+>1 : 1
+
+stringIndex[s].toFixed();
+>stringIndex[s].toFixed() : string
+>stringIndex[s].toFixed : (fractionDigits?: number) => string
+>stringIndex[s] : number
+>stringIndex : { [x: string]: number; }
+>s : string
+>toFixed : (fractionDigits?: number) => string
+
+

tests/cases/compiler/checkJsObjectLiteralIndexSignatures.ts

@@ -0,0 +1,15 @@
+// @allowJs: true
+// @noImplicitAny: true
+// @outDir: ./out
+// @filename: file.js
+// @ts-check
+
+let n = Math.random();
+let s = `${n}`;
+
+const numericIndex = { [n]: 1 };
+numericIndex[n].toFixed();
+
+const stringIndex = { [s]: 1 };
+stringIndex[s].toFixed();
+