Port tsgo PR 1284

Author: jakebailey

src/compiler/types.ts

@@ -6265,6 +6265,12 @@ export interface SerializedTypeEntry {
     trackedSymbols: readonly TrackedSymbol[] | undefined;
 }
 
+// Note that for types of different kinds, the numeric values of TypeFlags determine the order
+// computed by the CompareTypes function and therefore the order of constituent types in union types.
+// Since union type processing often bails out early when a result is known, it is important to order
+// TypeFlags in increasing order of potential type complexity. In particular, indexed access and
+// conditional types should sort last as those types are potentially recursive and possibly infinite.
+
 // dprint-ignore
 export const enum TypeFlags {
     Any             = 1 << 0,
@@ -6289,11 +6295,11 @@ export const enum TypeFlags {
     TypeParameter   = 1 << 19,  // Type parameter
     Object          = 1 << 20,  // Object type
     Index           = 1 << 21,  // keyof T
-    IndexedAccess   = 1 << 22,  // T[K]
-    Conditional     = 1 << 23,  // T extends U ? X : Y
+    TemplateLiteral = 1 << 22,  // Template literal type
+    StringMapping   = 1 << 23,  // Uppercase/Lowercase type
     Substitution    = 1 << 24,  // Type parameter substitution
-    TemplateLiteral = 1 << 25,  // Template literal type
-    StringMapping   = 1 << 26,  // Uppercase/Lowercase type
+    IndexedAccess   = 1 << 25,  // T[K]
+    Conditional     = 1 << 26,  // T extends U ? X : Y
     Union           = 1 << 27,  // Union (T | U)
     Intersection    = 1 << 28,  // Intersection (T & U)
     /** @internal */

tests/baselines/reference/api/typescript.d.ts

@@ -6590,19 +6590,19 @@ declare namespace ts {
         TypeParameter = 524288,
         Object = 1048576,
         Index = 2097152,
-        IndexedAccess = 4194304,
-        Conditional = 8388608,
+        TemplateLiteral = 4194304,
+        StringMapping = 8388608,
         Substitution = 16777216,
-        TemplateLiteral = 33554432,
-        StringMapping = 67108864,
+        IndexedAccess = 33554432,
+        Conditional = 67108864,
         Union = 134217728,
         Intersection = 268435456,
         Literal = 15360,
         Unit = 97292,
         Freshable = 80896,
         StringOrNumberLiteral = 3072,
         PossiblyFalsy = 15868,
-        StringLike = 100664352,
+        StringLike = 12583968,
         NumberLike = 67648,
         BigIntLike = 8320,
         BooleanLike = 4352,
@@ -6611,9 +6611,9 @@ declare namespace ts {
         VoidLike = 20,
         UnionOrIntersection = 402653184,
         StructuredType = 403701760,
-        TypeVariable = 4718592,
-        InstantiableNonPrimitive = 29884416,
-        InstantiablePrimitive = 102760448,
+        TypeVariable = 34078720,
+        InstantiableNonPrimitive = 117964800,
+        InstantiablePrimitive = 14680064,
         Instantiable = 132644864,
         StructuredOrInstantiable = 536346624,
         Narrowable = 536575971,

tests/baselines/reference/awaitedTypeNoLib.errors.txt

@@ -10,7 +10,7 @@ error TS2318: Cannot find global type 'String'.
 awaitedTypeNoLib.ts(3,15): error TS2304: Cannot find name 'PromiseLike'.
 awaitedTypeNoLib.ts(18,27): error TS2345: Argument of type 'Thenable<NotPromise<TResult>> | NotPromise<TResult>' is not assignable to parameter of type 'Thenable<TResult>'.
   Type 'NotPromise<TResult>' is not assignable to type 'Thenable<TResult>'.
-    Type '(TResult extends PromiseLike<unknown> ? never : TResult) | TResult' is not assignable to type 'Thenable<TResult>'.
+    Type 'TResult | (TResult extends PromiseLike<unknown> ? never : TResult)' is not assignable to type 'Thenable<TResult>'.
       Type 'Thenable<unknown> & TResult' is not assignable to type 'Thenable<TResult>'.
         Type 'unknown' is not assignable to type 'TResult'.
           'TResult' could be instantiated with an arbitrary type which could be unrelated to 'unknown'.
@@ -49,7 +49,7 @@ awaitedTypeNoLib.ts(18,27): error TS2345: Argument of type 'Thenable<NotPromise<
                               ~~~~~~
 !!! error TS2345: Argument of type 'Thenable<NotPromise<TResult>> | NotPromise<TResult>' is not assignable to parameter of type 'Thenable<TResult>'.
 !!! error TS2345:   Type 'NotPromise<TResult>' is not assignable to type 'Thenable<TResult>'.
-!!! error TS2345:     Type '(TResult extends PromiseLike<unknown> ? never : TResult) | TResult' is not assignable to type 'Thenable<TResult>'.
+!!! error TS2345:     Type 'TResult | (TResult extends PromiseLike<unknown> ? never : TResult)' is not assignable to type 'Thenable<TResult>'.
 !!! error TS2345:       Type 'Thenable<unknown> & TResult' is not assignable to type 'Thenable<TResult>'.
 !!! error TS2345:         Type 'unknown' is not assignable to type 'TResult'.
 !!! error TS2345:           'TResult' could be instantiated with an arbitrary type which could be unrelated to 'unknown'.

tests/baselines/reference/partiallyNamedTuples2.types

@@ -49,11 +49,11 @@ const matches = x.get(id1);
 >        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 >x.get(id1) : Iterable<[id2: string, object]>
 >           : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
->x.get : <Key extends [] | [id1: string] | [id1: string, id2: string]>(...key: Key) => GetResult<[id1: string, id2: string], Key, object>
+>x.get : <Key extends [id1: string, id2: string] | [id1: string] | []>(...key: Key) => GetResult<[id1: string, id2: string], Key, object>
 >      : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 >x : MultiKeyMap<[id1: string, id2: string], object>
 >  : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
->get : <Key extends [] | [id1: string] | [id1: string, id2: string]>(...key: Key) => GetResult<[id1: string, id2: string], Key, object>
+>get : <Key extends [id1: string, id2: string] | [id1: string] | []>(...key: Key) => GetResult<[id1: string, id2: string], Key, object>
 >    : ^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 >id1 : string
 >    : ^^^^^^