Eliminate redundant or meaningless elaborations in type relations (#47738)

* Eliminate redundant or meaningless elaborations in type relations

* Accept new baselines

* Add resetErrorInfo (though, oddly, shouldn't be necessary)

* Less aggressive reduction in second pass union/intersection checks

* Accept new baselines

* Restructure and back off a little bit more

* Only cache union/intersection relations once

* Accept new baselines

* Properly cache identity relations, clean up error reporting

* Move more logic to cached side of relation checks

* Optimize and remove more redundant elaborations

* Accept new baselines

* Remove unnecessary error state capture

* More optimizing

* Cache isWeakType computation

* Revert "Cache isWeakType computation"

This reverts commit 25a71c4.

* Address CR feedback

* Accept new baselines

Author: ahejlsberg

src/compiler/checker.ts

@@ -871,6 +871,14 @@
         "category": "Error",
         "code": 1269
     },
+    "Decorator function return type '{0}' is not assignable to type '{1}'.": {
+        "category": "Error",
+        "code": 1270
+    },
+    "Decorator function return type is '{0}' but is expected to be 'void' or 'any'.": {
+        "category": "Error",
+        "code": 1271
+    },
 
     "'with' statements are not allowed in an async function block.": {
         "category": "Error",

src/compiler/diagnosticMessages.json

@@ -5175,6 +5175,8 @@ namespace ts {
         ESSymbolLike = ESSymbol | UniqueESSymbol,
         VoidLike = Void | Undefined,
         /* @internal */
+        DefinitelyNonNullable = StringLike | NumberLike | BigIntLike | BooleanLike | EnumLike | ESSymbolLike | Object | NonPrimitive,
+        /* @internal */
         DisjointDomains = NonPrimitive | StringLike | NumberLike | BigIntLike | BooleanLike | ESSymbolLike | VoidLike | Null,
         UnionOrIntersection = Union | Intersection,
         StructuredType = Object | Union | Intersection,

src/compiler/types.ts

@@ -20,7 +20,6 @@ tests/cases/compiler/bigintWithLib.ts(31,35): error TS2769: No overload matches
     Argument of type 'number[]' is not assignable to parameter of type 'Iterable<bigint>'.
   Overload 3 of 3, '(buffer: ArrayBufferLike, byteOffset?: number, length?: number): BigUint64Array', gave the following error.
     Argument of type 'number[]' is not assignable to parameter of type 'ArrayBufferLike'.
-      Type 'number[]' is not assignable to type 'SharedArrayBuffer'.
 tests/cases/compiler/bigintWithLib.ts(36,13): error TS2540: Cannot assign to 'length' because it is a read-only property.
 tests/cases/compiler/bigintWithLib.ts(43,25): error TS2345: Argument of type 'number' is not assignable to parameter of type 'bigint'.
 tests/cases/compiler/bigintWithLib.ts(46,26): error TS2345: Argument of type 'number' is not assignable to parameter of type 'bigint'.
@@ -84,7 +83,6 @@ tests/cases/compiler/bigintWithLib.ts(46,26): error TS2345: Argument of type 'nu
 !!! error TS2769:     Argument of type 'number[]' is not assignable to parameter of type 'Iterable<bigint>'.
 !!! error TS2769:   Overload 3 of 3, '(buffer: ArrayBufferLike, byteOffset?: number, length?: number): BigUint64Array', gave the following error.
 !!! error TS2769:     Argument of type 'number[]' is not assignable to parameter of type 'ArrayBufferLike'.
-!!! error TS2769:       Type 'number[]' is not assignable to type 'SharedArrayBuffer'.
     bigUintArray = new BigUint64Array(new ArrayBuffer(80));
     bigUintArray = new BigUint64Array(new ArrayBuffer(80), 8);
     bigUintArray = new BigUint64Array(new ArrayBuffer(80), 8, 3);

tests/baselines/reference/bigintWithLib.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/conformance/jsdoc/0.js(5,3): error TS2322: Type 'number' is not assignable to type 'string | undefined'.
+tests/cases/conformance/jsdoc/0.js(5,3): error TS2322: Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/jsdoc/0.js(8,7): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/jsdoc/0.js(11,20): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/jsdoc/0.js(13,15): error TS2322: Type 'string' is not assignable to type 'number'.
@@ -15,7 +15,7 @@ tests/cases/conformance/jsdoc/0.js(22,22): error TS2345: Argument of type 'strin
       /** @type {string|undefined} */
       bar: 42,
       ~~~~~~~
-!!! error TS2322: Type 'number' is not assignable to type 'string | undefined'.
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
       /** @type {function(number): number} */
       method1(n1) {
           return "42";

tests/baselines/reference/checkJsdocTypeTagOnObjectProperty2.errors.txt

@@ -1,8 +1,6 @@
 tests/cases/conformance/jsx/file.tsx(24,28): error TS2551: Property 'NAme' does not exist on type 'IUser'. Did you mean 'Name'?
 tests/cases/conformance/jsx/file.tsx(36,15): error TS2322: Type '(user: IUser) => Element' is not assignable to type 'boolean | any[] | ReactChild'.
-  Type '(user: IUser) => Element' is missing the following properties from type 'ReactElement<any>': type, props
 tests/cases/conformance/jsx/file.tsx(39,15): error TS2322: Type '(user: IUser) => Element' is not assignable to type 'boolean | any[] | ReactChild'.
-  Type '(user: IUser) => Element' is missing the following properties from type 'ReactElement<any>': type, props
 
 
 ==== tests/cases/conformance/jsx/file.tsx (3 errors) ====
@@ -51,7 +49,6 @@ tests/cases/conformance/jsx/file.tsx(39,15): error TS2322: Type '(user: IUser) =
                 ) }
     ~~~~~~~~~~~~~
 !!! error TS2322: Type '(user: IUser) => Element' is not assignable to type 'boolean | any[] | ReactChild'.
-!!! error TS2322:   Type '(user: IUser) => Element' is missing the following properties from type 'ReactElement<any>': type, props
 !!! related TS6212 tests/cases/conformance/jsx/file.tsx:36:15: Did you mean to call this expression?
                 { user => (
                   ~~~~~~~~~
@@ -60,7 +57,6 @@ tests/cases/conformance/jsx/file.tsx(39,15): error TS2322: Type '(user: IUser) =
                 ) }
     ~~~~~~~~~~~~~
 !!! error TS2322: Type '(user: IUser) => Element' is not assignable to type 'boolean | any[] | ReactChild'.
-!!! error TS2322:   Type '(user: IUser) => Element' is missing the following properties from type 'ReactElement<any>': type, props
 !!! related TS6212 tests/cases/conformance/jsx/file.tsx:39:15: Did you mean to call this expression?
             </FetchUser>
         );