Accept new baselines

2026-05-15 12:51:30 -05:00 · 2018-05-21 16:44:03 -07:00
parent 9d4096f9c4
commit b31c414a31
3 changed files with 377 additions and 44 deletions
--- a/tests/baselines/reference/literalTypeWidening.js
+++ b/tests/baselines/reference/literalTypeWidening.js
@@ -60,6 +60,18 @@ function f5() {
    let v4 = c4;
 }

+declare function widening<T>(x: T): T;
+declare function nonWidening<T extends string | number | symbol>(x: T): T;
+
+function f6(cond: boolean) {
+    let x1 = widening('a');
+    let x2 = widening(10);
+    let x3 = widening(cond ? 'a' : 10);
+    let y1 = nonWidening('a');
+    let y2 = nonWidening(10);
+    let y3 = nonWidening(cond ? 'a' : 10);
+}
+
 // Repro from #10898

 type FAILURE = "FAILURE";
@@ -95,10 +107,33 @@ type TestEvent = "onmouseover" | "onmouseout";

 function onMouseOver(): TestEvent { return "onmouseover"; }

-let x = onMouseOver();
+let x = onMouseOver();
+
+// Repro from #23649
+
+export function Set<K extends string>(...keys: K[]): Record<K, true | undefined> {
+  const result = {} as Record<K, true | undefined>
+  keys.forEach(key => result[key] = true)
+  return result
+}
+
+export function keys<K extends string, V>(obj: Record<K, V>): K[] {
+  return Object.keys(obj) as K[]
+}
+
+type Obj = { code: LangCode }
+
+const langCodeSet = Set('fr', 'en', 'es', 'it', 'nl')
+export type LangCode = keyof typeof langCodeSet
+export const langCodes = keys(langCodeSet)
+
+const arr: Obj[] = langCodes.map(code => ({ code }))
+

 //// [literalTypeWidening.js]
+"use strict";
 // Widening vs. non-widening literal types
+exports.__esModule = true;
 function f1() {
    var c1 = "hello"; // Widening type "hello"
    var v1 = c1; // Type string
@@ -153,6 +188,14 @@ function f5() {
    var c4 = "foo";
    var v4 = c4;
 }
+function f6(cond) {
+    var x1 = widening('a');
+    var x2 = widening(10);
+    var x3 = widening(cond ? 'a' : 10);
+    var y1 = nonWidening('a');
+    var y2 = nonWidening(10);
+    var y3 = nonWidening(cond ? 'a' : 10);
+}
 var FAILURE = "FAILURE";
 function doWork() {
    return FAILURE;
@@ -172,3 +215,21 @@ if (isSuccess(result)) {
 }
 function onMouseOver() { return "onmouseover"; }
 var x = onMouseOver();
+// Repro from #23649
+function Set() {
+    var keys = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        keys[_i] = arguments[_i];
+    }
+    var result = {};
+    keys.forEach(function (key) { return result[key] = true; });
+    return result;
+}
+exports.Set = Set;
+function keys(obj) {
+    return Object.keys(obj);
+}
+exports.keys = keys;
+var langCodeSet = Set('fr', 'en', 'es', 'it', 'nl');
+exports.langCodes = keys(langCodeSet);
+var arr = exports.langCodes.map(function (code) { return ({ code: code }); });
--- a/tests/baselines/reference/literalTypeWidening.symbols
+++ b/tests/baselines/reference/literalTypeWidening.symbols
@@ -197,89 +197,206 @@ function f5() {
 >c4 : Symbol(c4, Decl(literalTypeWidening.ts, 57, 9))
 }

+declare function widening<T>(x: T): T;
+>widening : Symbol(widening, Decl(literalTypeWidening.ts, 59, 1))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 61, 26))
+>x : Symbol(x, Decl(literalTypeWidening.ts, 61, 29))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 61, 26))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 61, 26))
+
+declare function nonWidening<T extends string | number | symbol>(x: T): T;
+>nonWidening : Symbol(nonWidening, Decl(literalTypeWidening.ts, 61, 38))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 62, 29))
+>x : Symbol(x, Decl(literalTypeWidening.ts, 62, 65))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 62, 29))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 62, 29))
+
+function f6(cond: boolean) {
+>f6 : Symbol(f6, Decl(literalTypeWidening.ts, 62, 74))
+>cond : Symbol(cond, Decl(literalTypeWidening.ts, 64, 12))
+
+    let x1 = widening('a');
+>x1 : Symbol(x1, Decl(literalTypeWidening.ts, 65, 7))
+>widening : Symbol(widening, Decl(literalTypeWidening.ts, 59, 1))
+
+    let x2 = widening(10);
+>x2 : Symbol(x2, Decl(literalTypeWidening.ts, 66, 7))
+>widening : Symbol(widening, Decl(literalTypeWidening.ts, 59, 1))
+
+    let x3 = widening(cond ? 'a' : 10);
+>x3 : Symbol(x3, Decl(literalTypeWidening.ts, 67, 7))
+>widening : Symbol(widening, Decl(literalTypeWidening.ts, 59, 1))
+>cond : Symbol(cond, Decl(literalTypeWidening.ts, 64, 12))
+
+    let y1 = nonWidening('a');
+>y1 : Symbol(y1, Decl(literalTypeWidening.ts, 68, 7))
+>nonWidening : Symbol(nonWidening, Decl(literalTypeWidening.ts, 61, 38))
+
+    let y2 = nonWidening(10);
+>y2 : Symbol(y2, Decl(literalTypeWidening.ts, 69, 7))
+>nonWidening : Symbol(nonWidening, Decl(literalTypeWidening.ts, 61, 38))
+
+    let y3 = nonWidening(cond ? 'a' : 10);
+>y3 : Symbol(y3, Decl(literalTypeWidening.ts, 70, 7))
+>nonWidening : Symbol(nonWidening, Decl(literalTypeWidening.ts, 61, 38))
+>cond : Symbol(cond, Decl(literalTypeWidening.ts, 64, 12))
+}
+
 // Repro from #10898

 type FAILURE = "FAILURE";
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))

 const FAILURE = "FAILURE";
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))

 type Result<T> = T | FAILURE;
->Result : Symbol(Result, Decl(literalTypeWidening.ts, 64, 26))
->T : Symbol(T, Decl(literalTypeWidening.ts, 66, 12))
->T : Symbol(T, Decl(literalTypeWidening.ts, 66, 12))
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>Result : Symbol(Result, Decl(literalTypeWidening.ts, 76, 26))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 78, 12))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 78, 12))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))

 function doWork<T>(): Result<T> {
->doWork : Symbol(doWork, Decl(literalTypeWidening.ts, 66, 29))
->T : Symbol(T, Decl(literalTypeWidening.ts, 68, 16))
->Result : Symbol(Result, Decl(literalTypeWidening.ts, 64, 26))
->T : Symbol(T, Decl(literalTypeWidening.ts, 68, 16))
+>doWork : Symbol(doWork, Decl(literalTypeWidening.ts, 78, 29))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 80, 16))
+>Result : Symbol(Result, Decl(literalTypeWidening.ts, 76, 26))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 80, 16))

  return FAILURE;
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))
 }

 function isSuccess<T>(result: Result<T>): result is T {
->isSuccess : Symbol(isSuccess, Decl(literalTypeWidening.ts, 70, 1))
->T : Symbol(T, Decl(literalTypeWidening.ts, 72, 19))
->result : Symbol(result, Decl(literalTypeWidening.ts, 72, 22))
->Result : Symbol(Result, Decl(literalTypeWidening.ts, 64, 26))
->T : Symbol(T, Decl(literalTypeWidening.ts, 72, 19))
->result : Symbol(result, Decl(literalTypeWidening.ts, 72, 22))
->T : Symbol(T, Decl(literalTypeWidening.ts, 72, 19))
+>isSuccess : Symbol(isSuccess, Decl(literalTypeWidening.ts, 82, 1))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 84, 19))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 84, 22))
+>Result : Symbol(Result, Decl(literalTypeWidening.ts, 76, 26))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 84, 19))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 84, 22))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 84, 19))

  return !isFailure(result);
->isFailure : Symbol(isFailure, Decl(literalTypeWidening.ts, 74, 1))
->result : Symbol(result, Decl(literalTypeWidening.ts, 72, 22))
+>isFailure : Symbol(isFailure, Decl(literalTypeWidening.ts, 86, 1))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 84, 22))
 }

 function isFailure<T>(result: Result<T>): result is FAILURE {
->isFailure : Symbol(isFailure, Decl(literalTypeWidening.ts, 74, 1))
->T : Symbol(T, Decl(literalTypeWidening.ts, 76, 19))
->result : Symbol(result, Decl(literalTypeWidening.ts, 76, 22))
->Result : Symbol(Result, Decl(literalTypeWidening.ts, 64, 26))
->T : Symbol(T, Decl(literalTypeWidening.ts, 76, 19))
->result : Symbol(result, Decl(literalTypeWidening.ts, 76, 22))
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>isFailure : Symbol(isFailure, Decl(literalTypeWidening.ts, 86, 1))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 88, 19))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 88, 22))
+>Result : Symbol(Result, Decl(literalTypeWidening.ts, 76, 26))
+>T : Symbol(T, Decl(literalTypeWidening.ts, 88, 19))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 88, 22))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))

  return result === FAILURE;
->result : Symbol(result, Decl(literalTypeWidening.ts, 76, 22))
->FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 59, 1), Decl(literalTypeWidening.ts, 64, 5))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 88, 22))
+>FAILURE : Symbol(FAILURE, Decl(literalTypeWidening.ts, 71, 1), Decl(literalTypeWidening.ts, 76, 5))
 }

 function increment(x: number): number {
->increment : Symbol(increment, Decl(literalTypeWidening.ts, 78, 1))
->x : Symbol(x, Decl(literalTypeWidening.ts, 80, 19))
+>increment : Symbol(increment, Decl(literalTypeWidening.ts, 90, 1))
+>x : Symbol(x, Decl(literalTypeWidening.ts, 92, 19))

  return x + 1;
->x : Symbol(x, Decl(literalTypeWidening.ts, 80, 19))
+>x : Symbol(x, Decl(literalTypeWidening.ts, 92, 19))
 }

 let result = doWork<number>();
->result : Symbol(result, Decl(literalTypeWidening.ts, 84, 3))
->doWork : Symbol(doWork, Decl(literalTypeWidening.ts, 66, 29))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 96, 3))
+>doWork : Symbol(doWork, Decl(literalTypeWidening.ts, 78, 29))

 if (isSuccess(result)) {
->isSuccess : Symbol(isSuccess, Decl(literalTypeWidening.ts, 70, 1))
->result : Symbol(result, Decl(literalTypeWidening.ts, 84, 3))
+>isSuccess : Symbol(isSuccess, Decl(literalTypeWidening.ts, 82, 1))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 96, 3))

  increment(result);
->increment : Symbol(increment, Decl(literalTypeWidening.ts, 78, 1))
->result : Symbol(result, Decl(literalTypeWidening.ts, 84, 3))
+>increment : Symbol(increment, Decl(literalTypeWidening.ts, 90, 1))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 96, 3))
 }

 // Repro from #10898

 type TestEvent = "onmouseover" | "onmouseout";
->TestEvent : Symbol(TestEvent, Decl(literalTypeWidening.ts, 88, 1))
+>TestEvent : Symbol(TestEvent, Decl(literalTypeWidening.ts, 100, 1))

 function onMouseOver(): TestEvent { return "onmouseover"; }
->onMouseOver : Symbol(onMouseOver, Decl(literalTypeWidening.ts, 92, 46))
->TestEvent : Symbol(TestEvent, Decl(literalTypeWidening.ts, 88, 1))
+>onMouseOver : Symbol(onMouseOver, Decl(literalTypeWidening.ts, 104, 46))
+>TestEvent : Symbol(TestEvent, Decl(literalTypeWidening.ts, 100, 1))

 let x = onMouseOver();
->x : Symbol(x, Decl(literalTypeWidening.ts, 96, 3))
->onMouseOver : Symbol(onMouseOver, Decl(literalTypeWidening.ts, 92, 46))
+>x : Symbol(x, Decl(literalTypeWidening.ts, 108, 3))
+>onMouseOver : Symbol(onMouseOver, Decl(literalTypeWidening.ts, 104, 46))
+
+// Repro from #23649
+
+export function Set<K extends string>(...keys: K[]): Record<K, true | undefined> {
+>Set : Symbol(Set, Decl(literalTypeWidening.ts, 108, 22))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 112, 20))
+>keys : Symbol(keys, Decl(literalTypeWidening.ts, 112, 38))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 112, 20))
+>Record : Symbol(Record, Decl(lib.d.ts, --, --))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 112, 20))
+
+  const result = {} as Record<K, true | undefined>
+>result : Symbol(result, Decl(literalTypeWidening.ts, 113, 7))
+>Record : Symbol(Record, Decl(lib.d.ts, --, --))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 112, 20))
+
+  keys.forEach(key => result[key] = true)
+>keys.forEach : Symbol(Array.forEach, Decl(lib.d.ts, --, --))
+>keys : Symbol(keys, Decl(literalTypeWidening.ts, 112, 38))
+>forEach : Symbol(Array.forEach, Decl(lib.d.ts, --, --))
+>key : Symbol(key, Decl(literalTypeWidening.ts, 114, 15))
+>result : Symbol(result, Decl(literalTypeWidening.ts, 113, 7))
+>key : Symbol(key, Decl(literalTypeWidening.ts, 114, 15))
+
+  return result
+>result : Symbol(result, Decl(literalTypeWidening.ts, 113, 7))
+}
+
+export function keys<K extends string, V>(obj: Record<K, V>): K[] {
+>keys : Symbol(keys, Decl(literalTypeWidening.ts, 116, 1))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 118, 21))
+>V : Symbol(V, Decl(literalTypeWidening.ts, 118, 38))
+>obj : Symbol(obj, Decl(literalTypeWidening.ts, 118, 42))
+>Record : Symbol(Record, Decl(lib.d.ts, --, --))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 118, 21))
+>V : Symbol(V, Decl(literalTypeWidening.ts, 118, 38))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 118, 21))
+
+  return Object.keys(obj) as K[]
+>Object.keys : Symbol(ObjectConstructor.keys, Decl(lib.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>keys : Symbol(ObjectConstructor.keys, Decl(lib.d.ts, --, --))
+>obj : Symbol(obj, Decl(literalTypeWidening.ts, 118, 42))
+>K : Symbol(K, Decl(literalTypeWidening.ts, 118, 21))
+}
+
+type Obj = { code: LangCode }
+>Obj : Symbol(Obj, Decl(literalTypeWidening.ts, 120, 1))
+>code : Symbol(code, Decl(literalTypeWidening.ts, 122, 12))
+>LangCode : Symbol(LangCode, Decl(literalTypeWidening.ts, 124, 53))
+
+const langCodeSet = Set('fr', 'en', 'es', 'it', 'nl')
+>langCodeSet : Symbol(langCodeSet, Decl(literalTypeWidening.ts, 124, 5))
+>Set : Symbol(Set, Decl(literalTypeWidening.ts, 108, 22))
+
+export type LangCode = keyof typeof langCodeSet
+>LangCode : Symbol(LangCode, Decl(literalTypeWidening.ts, 124, 53))
+>langCodeSet : Symbol(langCodeSet, Decl(literalTypeWidening.ts, 124, 5))
+
+export const langCodes = keys(langCodeSet)
+>langCodes : Symbol(langCodes, Decl(literalTypeWidening.ts, 126, 12))
+>keys : Symbol(keys, Decl(literalTypeWidening.ts, 116, 1))
+>langCodeSet : Symbol(langCodeSet, Decl(literalTypeWidening.ts, 124, 5))
+
+const arr: Obj[] = langCodes.map(code => ({ code }))
+>arr : Symbol(arr, Decl(literalTypeWidening.ts, 128, 5))
+>Obj : Symbol(Obj, Decl(literalTypeWidening.ts, 120, 1))
+>langCodes.map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>langCodes : Symbol(langCodes, Decl(literalTypeWidening.ts, 126, 12))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --))
+>code : Symbol(code, Decl(literalTypeWidening.ts, 128, 33))
+>code : Symbol(code, Decl(literalTypeWidening.ts, 128, 43))

--- a/tests/baselines/reference/literalTypeWidening.types
+++ b/tests/baselines/reference/literalTypeWidening.types
@@ -219,6 +219,67 @@ function f5() {
 >c4 : "foo"
 }

+declare function widening<T>(x: T): T;
+>widening : <T>(x: T) => T
+>T : T
+>x : T
+>T : T
+>T : T
+
+declare function nonWidening<T extends string | number | symbol>(x: T): T;
+>nonWidening : <T extends string | number | symbol>(x: T) => T
+>T : T
+>x : T
+>T : T
+>T : T
+
+function f6(cond: boolean) {
+>f6 : (cond: boolean) => void
+>cond : boolean
+
+    let x1 = widening('a');
+>x1 : string
+>widening('a') : "a"
+>widening : <T>(x: T) => T
+>'a' : "a"
+
+    let x2 = widening(10);
+>x2 : number
+>widening(10) : 10
+>widening : <T>(x: T) => T
+>10 : 10
+
+    let x3 = widening(cond ? 'a' : 10);
+>x3 : string | number
+>widening(cond ? 'a' : 10) : "a" | 10
+>widening : <T>(x: T) => T
+>cond ? 'a' : 10 : "a" | 10
+>cond : boolean
+>'a' : "a"
+>10 : 10
+
+    let y1 = nonWidening('a');
+>y1 : "a"
+>nonWidening('a') : "a"
+>nonWidening : <T extends string | number | symbol>(x: T) => T
+>'a' : "a"
+
+    let y2 = nonWidening(10);
+>y2 : 10
+>nonWidening(10) : 10
+>nonWidening : <T extends string | number | symbol>(x: T) => T
+>10 : 10
+
+    let y3 = nonWidening(cond ? 'a' : 10);
+>y3 : "a" | 10
+>nonWidening(cond ? 'a' : 10) : "a" | 10
+>nonWidening : <T extends string | number | symbol>(x: T) => T
+>cond ? 'a' : 10 : "a" | 10
+>cond : boolean
+>'a' : "a"
+>10 : 10
+}
+
 // Repro from #10898

 type FAILURE = "FAILURE";
@@ -316,3 +377,97 @@ let x = onMouseOver();
 >onMouseOver() : TestEvent
 >onMouseOver : () => TestEvent

+// Repro from #23649
+
+export function Set<K extends string>(...keys: K[]): Record<K, true | undefined> {
+>Set : <K extends string>(...keys: K[]) => Record<K, true>
+>K : K
+>keys : K[]
+>K : K
+>Record : Record<K, T>
+>K : K
+>true : true
+
+  const result = {} as Record<K, true | undefined>
+>result : Record<K, true>
+>{} as Record<K, true | undefined> : Record<K, true>
+>{} : {}
+>Record : Record<K, T>
+>K : K
+>true : true
+
+  keys.forEach(key => result[key] = true)
+>keys.forEach(key => result[key] = true) : void
+>keys.forEach : (callbackfn: (value: K, index: number, array: K[]) => void, thisArg?: any) => void
+>keys : K[]
+>forEach : (callbackfn: (value: K, index: number, array: K[]) => void, thisArg?: any) => void
+>key => result[key] = true : (key: K) => boolean
+>key : K
+>result[key] = true : true
+>result[key] : Record<K, true>[K]
+>result : Record<K, true>
+>key : K
+>true : true
+
+  return result
+>result : Record<K, true>
+}
+
+export function keys<K extends string, V>(obj: Record<K, V>): K[] {
+>keys : <K extends string, V>(obj: Record<K, V>) => K[]
+>K : K
+>V : V
+>obj : Record<K, V>
+>Record : Record<K, T>
+>K : K
+>V : V
+>K : K
+
+  return Object.keys(obj) as K[]
+>Object.keys(obj) as K[] : K[]
+>Object.keys(obj) : string[]
+>Object.keys : (o: {}) => string[]
+>Object : ObjectConstructor
+>keys : (o: {}) => string[]
+>obj : Record<K, V>
+>K : K
+}
+
+type Obj = { code: LangCode }
+>Obj : Obj
+>code : "fr" | "en" | "es" | "it" | "nl"
+>LangCode : "fr" | "en" | "es" | "it" | "nl"
+
+const langCodeSet = Set('fr', 'en', 'es', 'it', 'nl')
+>langCodeSet : Record<"fr" | "en" | "es" | "it" | "nl", true>
+>Set('fr', 'en', 'es', 'it', 'nl') : Record<"fr" | "en" | "es" | "it" | "nl", true>
+>Set : <K extends string>(...keys: K[]) => Record<K, true>
+>'fr' : "fr"
+>'en' : "en"
+>'es' : "es"
+>'it' : "it"
+>'nl' : "nl"
+
+export type LangCode = keyof typeof langCodeSet
+>LangCode : "fr" | "en" | "es" | "it" | "nl"
+>langCodeSet : Record<"fr" | "en" | "es" | "it" | "nl", true>
+
+export const langCodes = keys(langCodeSet)
+>langCodes : ("fr" | "en" | "es" | "it" | "nl")[]
+>keys(langCodeSet) : ("fr" | "en" | "es" | "it" | "nl")[]
+>keys : <K extends string, V>(obj: Record<K, V>) => K[]
+>langCodeSet : Record<"fr" | "en" | "es" | "it" | "nl", true>
+
+const arr: Obj[] = langCodes.map(code => ({ code }))
+>arr : Obj[]
+>Obj : Obj
+>langCodes.map(code => ({ code })) : { code: "fr" | "en" | "es" | "it" | "nl"; }[]
+>langCodes.map : <U>(callbackfn: (value: "fr" | "en" | "es" | "it" | "nl", index: number, array: ("fr" | "en" | "es" | "it" | "nl")[]) => U, thisArg?: any) => U[]
+>langCodes : ("fr" | "en" | "es" | "it" | "nl")[]
+>map : <U>(callbackfn: (value: "fr" | "en" | "es" | "it" | "nl", index: number, array: ("fr" | "en" | "es" | "it" | "nl")[]) => U, thisArg?: any) => U[]
+>code => ({ code }) : (code: "fr" | "en" | "es" | "it" | "nl") => { code: "fr" | "en" | "es" | "it" | "nl"; }
+>code : "fr" | "en" | "es" | "it" | "nl"
+>({ code }) : { code: "fr" | "en" | "es" | "it" | "nl"; }
+>{ code } : { code: "fr" | "en" | "es" | "it" | "nl"; }
+>code : "fr" | "en" | "es" | "it" | "nl"
+