Add tests

Author: ahejlsberg

tests/baselines/reference/deferredLookupTypeResolution2.errors.txt

@@ -0,0 +1,31 @@
+tests/cases/compiler/deferredLookupTypeResolution2.ts(14,13): error TS2536: Type '({ [K in S]: "true"; } & { [key: string]: "false"; })["1"]' cannot be used to index type '{ true: "true"; }'.
+tests/cases/compiler/deferredLookupTypeResolution2.ts(19,21): error TS2536: Type '({ true: "otherwise"; } & { [k: string]: "true"; })[({ [K in S]: "true"; } & { [key: string]: "false"; })["1"]]' cannot be used to index type '{ true: "true"; }'.
+
+
+==== tests/cases/compiler/deferredLookupTypeResolution2.ts (2 errors) ====
+    // Repro from #17456
+    
+    type StringContains<S extends string, L extends string> = ({ [K in S]: 'true' } & { [key: string]: 'false'})[L];
+    
+    type ObjectHasKey<O, L extends string> = StringContains<keyof O, L>;
+    
+    type A<T> = ObjectHasKey<T, '0'>;
+    
+    type B = ObjectHasKey<[string, number], '1'>;  // "true"
+    type C = ObjectHasKey<[string, number], '2'>;  // "false"
+    type D = A<[string]>;  // "true"
+    
+    // Error, "false" not handled
+    type E<T> = { true: 'true' }[ObjectHasKey<T, '1'>];
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2536: Type '({ [K in S]: "true"; } & { [key: string]: "false"; })["1"]' cannot be used to index type '{ true: "true"; }'.
+    
+    type Juxtapose<T> = ({ true: 'otherwise' } & { [k: string]: 'true' })[ObjectHasKey<T, '1'>];
+    
+    // Error, "otherwise" is missing
+    type DeepError<T> = { true: 'true' }[Juxtapose<T>];
+                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2536: Type '({ true: "otherwise"; } & { [k: string]: "true"; })[({ [K in S]: "true"; } & { [key: string]: "false"; })["1"]]' cannot be used to index type '{ true: "true"; }'.
+    
+    type DeepOK<T> = { true: 'true', otherwise: 'false' }[Juxtapose<T>];
+    

tests/baselines/reference/deferredLookupTypeResolution2.js

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+//// [deferredLookupTypeResolution2.ts]
+// Repro from #17456
+
+type StringContains<S extends string, L extends string> = ({ [K in S]: 'true' } & { [key: string]: 'false'})[L];
+
+type ObjectHasKey<O, L extends string> = StringContains<keyof O, L>;
+
+type A<T> = ObjectHasKey<T, '0'>;
+
+type B = ObjectHasKey<[string, number], '1'>;  // "true"
+type C = ObjectHasKey<[string, number], '2'>;  // "false"
+type D = A<[string]>;  // "true"
+
+// Error, "false" not handled
+type E<T> = { true: 'true' }[ObjectHasKey<T, '1'>];
+
+type Juxtapose<T> = ({ true: 'otherwise' } & { [k: string]: 'true' })[ObjectHasKey<T, '1'>];
+
+// Error, "otherwise" is missing
+type DeepError<T> = { true: 'true' }[Juxtapose<T>];
+
+type DeepOK<T> = { true: 'true', otherwise: 'false' }[Juxtapose<T>];
+
+
+//// [deferredLookupTypeResolution2.js]
+"use strict";
+// Repro from #17456
+
+
+//// [deferredLookupTypeResolution2.d.ts]
+declare type StringContains<S extends string, L extends string> = ({
+    [K in S]: 'true';
+} & {
+    [key: string]: 'false';
+})[L];
+declare type ObjectHasKey<O, L extends string> = StringContains<keyof O, L>;
+declare type A<T> = ObjectHasKey<T, '0'>;
+declare type B = ObjectHasKey<[string, number], '1'>;
+declare type C = ObjectHasKey<[string, number], '2'>;
+declare type D = A<[string]>;
+declare type E<T> = {
+    true: 'true';
+}[ObjectHasKey<T, '1'>];
+declare type Juxtapose<T> = ({
+    true: 'otherwise';
+} & {
+    [k: string]: 'true';
+})[ObjectHasKey<T, '1'>];
+declare type DeepError<T> = {
+    true: 'true';
+}[Juxtapose<T>];
+declare type DeepOK<T> = {
+    true: 'true';
+    otherwise: 'false';
+}[Juxtapose<T>];

tests/cases/compiler/deferredLookupTypeResolution2.ts

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+// @strict: true
+// @declaration: true
+
+// Repro from #17456
+
+type StringContains<S extends string, L extends string> = ({ [K in S]: 'true' } & { [key: string]: 'false'})[L];
+
+type ObjectHasKey<O, L extends string> = StringContains<keyof O, L>;
+
+type A<T> = ObjectHasKey<T, '0'>;
+
+type B = ObjectHasKey<[string, number], '1'>;  // "true"
+type C = ObjectHasKey<[string, number], '2'>;  // "false"
+type D = A<[string]>;  // "true"
+
+// Error, "false" not handled
+type E<T> = { true: 'true' }[ObjectHasKey<T, '1'>];
+
+type Juxtapose<T> = ({ true: 'otherwise' } & { [k: string]: 'true' })[ObjectHasKey<T, '1'>];
+
+// Error, "otherwise" is missing
+type DeepError<T> = { true: 'true' }[Juxtapose<T>];
+
+type DeepOK<T> = { true: 'true', otherwise: 'false' }[Juxtapose<T>];