Port "Narrow types by satisfies expressions" (#1047)

Author: Andarist

internal/checker/flow.go

@@ -388,7 +388,7 @@ func (c *Checker) narrowType(f *FlowState, t *Type, expr *ast.Node, assumeTrue b
 		return c.narrowTypeByTruthiness(f, t, expr, assumeTrue)
 	case ast.KindCallExpression:
 		return c.narrowTypeByCallExpression(f, t, expr, assumeTrue)
-	case ast.KindParenthesizedExpression, ast.KindNonNullExpression:
+	case ast.KindParenthesizedExpression, ast.KindNonNullExpression, ast.KindSatisfiesExpression:
 		return c.narrowType(f, t, expr.Expression(), assumeTrue)
 	case ast.KindBinaryExpression:
 		return c.narrowTypeByBinaryExpression(f, t, expr.AsBinaryExpression(), assumeTrue)
@@ -1575,7 +1575,7 @@ func (c *Checker) isMatchingReference(source *ast.Node, target *ast.Node) bool {
 		return target.Kind == ast.KindThisKeyword
 	case ast.KindSuperKeyword:
 		return target.Kind == ast.KindSuperKeyword
-	case ast.KindNonNullExpression, ast.KindParenthesizedExpression:
+	case ast.KindNonNullExpression, ast.KindParenthesizedExpression, ast.KindSatisfiesExpression:
 		return c.isMatchingReference(source.Expression(), target)
 	case ast.KindPropertyAccessExpression, ast.KindElementAccessExpression:
 		if sourcePropertyName, ok := c.getAccessedPropertyName(source); ok {

testdata/baselines/reference/submodule/compiler/inferTypePredicates.errors.txt

@@ -20,12 +20,9 @@ inferTypePredicates.ts(115,7): error TS2322: Type 'string | number' is not assig
 inferTypePredicates.ts(133,7): error TS2322: Type 'object' is not assignable to type 'Date'.
   Type '{}' is missing the following properties from type 'Date': toDateString, toTimeString, toLocaleDateString, toLocaleTimeString, and 37 more.
 inferTypePredicates.ts(205,7): error TS2741: Property 'z' is missing in type 'C1' but required in type 'C2'.
-inferTypePredicates.ts(281,7): error TS2322: Type '(number | null)[]' is not assignable to type 'number[]'.
-  Type 'number | null' is not assignable to type 'number'.
-    Type 'null' is not assignable to type 'number'.
 
 
-==== inferTypePredicates.ts (12 errors) ====
+==== inferTypePredicates.ts (11 errors) ====
     // https://github.com/microsoft/TypeScript/issues/16069
 
     const numsOrNull = [1, 2, 3, 4, null];
@@ -341,10 +338,6 @@ inferTypePredicates.ts(281,7): error TS2322: Type '(number | null)[]' is not ass
 
     // https://github.com/microsoft/TypeScript/issues/60778
     const arrTest: Array<number> = [1, 2, null, 3].filter(
-          ~~~~~~~
-!!! error TS2322: Type '(number | null)[]' is not assignable to type 'number[]'.
-!!! error TS2322:   Type 'number | null' is not assignable to type 'number'.
-!!! error TS2322:     Type 'null' is not assignable to type 'number'.
       (x) => (x != null) satisfies boolean,
     );
 

testdata/baselines/reference/submodule/compiler/inferTypePredicates.errors.txt.diff

@@ -8,19 +8,9 @@
 +inferTypePredicates.ts(133,7): error TS2322: Type 'object' is not assignable to type 'Date'.
 +  Type '{}' is missing the following properties from type 'Date': toDateString, toTimeString, toLocaleDateString, toLocaleTimeString, and 37 more.
  inferTypePredicates.ts(205,7): error TS2741: Property 'z' is missing in type 'C1' but required in type 'C2'.
--
--
--==== inferTypePredicates.ts (11 errors) ====
-+inferTypePredicates.ts(281,7): error TS2322: Type '(number | null)[]' is not assignable to type 'number[]'.
-+  Type 'number | null' is not assignable to type 'number'.
-+    Type 'null' is not assignable to type 'number'.
-+
-+
-+==== inferTypePredicates.ts (12 errors) ====
-     // https://github.com/microsoft/TypeScript/issues/16069
-     
-     const numsOrNull = [1, 2, 3, 4, null];
-@@= skipped -167, +171 lines =@@
+
+
+@@= skipped -167, +168 lines =@@
      if (flakyIsDate(maybeDate)) {
        let t: Date = maybeDate;  // should error
            ~
@@ -29,15 +19,4 @@
 +!!! error TS2322:   Type '{}' is missing the following properties from type 'Date': toDateString, toTimeString, toLocaleDateString, toLocaleTimeString, and 37 more.
      } else {
        let t: object = maybeDate;  // should ok
-     }
-@@= skipped -152, +153 lines =@@
-     
-     // https://github.com/microsoft/TypeScript/issues/60778
-     const arrTest: Array<number> = [1, 2, null, 3].filter(
-+          ~~~~~~~
-+!!! error TS2322: Type '(number | null)[]' is not assignable to type 'number[]'.
-+!!! error TS2322:   Type 'number | null' is not assignable to type 'number'.
-+!!! error TS2322:     Type 'null' is not assignable to type 'number'.
-       (x) => (x != null) satisfies boolean,
-     );
-     
+     }

testdata/baselines/reference/submodule/compiler/inferTypePredicates.js

@@ -631,4 +631,4 @@ declare const foobarPred: (fb: {
 };
 // https://github.com/microsoft/TypeScript/issues/60778
 declare const arrTest: Array<number>;
-declare function isEmptyString(x: unknown): boolean;
+declare function isEmptyString(x: unknown): x is "";

testdata/baselines/reference/submodule/compiler/inferTypePredicates.js.diff

@@ -426,5 +426,4 @@
  };
 +// https://github.com/microsoft/TypeScript/issues/60778
  declare const arrTest: Array<number>;
--declare function isEmptyString(x: unknown): x is "";
-+declare function isEmptyString(x: unknown): boolean;
+ declare function isEmptyString(x: unknown): x is "";

testdata/baselines/reference/submodule/compiler/inferTypePredicates.types

@@ -1016,7 +1016,7 @@ if (foobarPred(foobar)) {
 // https://github.com/microsoft/TypeScript/issues/60778
 const arrTest: Array<number> = [1, 2, null, 3].filter(
 >arrTest : number[]
->[1, 2, null, 3].filter(  (x) => (x != null) satisfies boolean,) : (number | null)[]
+>[1, 2, null, 3].filter(  (x) => (x != null) satisfies boolean,) : number[]
 >[1, 2, null, 3].filter : { <S extends number | null>(predicate: (value: number | null, index: number, array: (number | null)[]) => value is S, thisArg?: any): S[]; (predicate: (value: number | null, index: number, array: (number | null)[]) => unknown, thisArg?: any): (number | null)[]; }
 >[1, 2, null, 3] : (number | null)[]
 >1 : 1
@@ -1025,7 +1025,7 @@ const arrTest: Array<number> = [1, 2, null, 3].filter(
 >filter : { <S extends number | null>(predicate: (value: number | null, index: number, array: (number | null)[]) => value is S, thisArg?: any): S[]; (predicate: (value: number | null, index: number, array: (number | null)[]) => unknown, thisArg?: any): (number | null)[]; }
 
   (x) => (x != null) satisfies boolean,
->(x) => (x != null) satisfies boolean : (x: number | null) => boolean
+>(x) => (x != null) satisfies boolean : (x: number | null) => x is number
 >x : number | null
 >(x != null) satisfies boolean : boolean
 >(x != null) : boolean
@@ -1035,7 +1035,7 @@ const arrTest: Array<number> = [1, 2, null, 3].filter(
 );
 
 function isEmptyString(x: unknown) {
->isEmptyString : (x: unknown) => boolean
+>isEmptyString : (x: unknown) => x is ""
 >x : unknown
 
   const rv = x === "";

testdata/baselines/reference/submodule/compiler/inferTypePredicates.types.diff

@@ -141,31 +141,4 @@
 +>foobarPred : (fb: { type: "foo"; foo: number; } | { type: "bar"; bar: string; }) => fb is { type: "foo"; foo: number; }
  >foobar : { type: "foo"; foo: number; } | { type: "bar"; bar: string; }
 
-   foobar.foo;
-@@= skipped -12, +12 lines =@@
- // https://github.com/microsoft/TypeScript/issues/60778
- const arrTest: Array<number> = [1, 2, null, 3].filter(
- >arrTest : number[]
-->[1, 2, null, 3].filter(  (x) => (x != null) satisfies boolean,) : number[]
-+>[1, 2, null, 3].filter(  (x) => (x != null) satisfies boolean,) : (number | null)[]
- >[1, 2, null, 3].filter : { <S extends number | null>(predicate: (value: number | null, index: number, array: (number | null)[]) => value is S, thisArg?: any): S[]; (predicate: (value: number | null, index: number, array: (number | null)[]) => unknown, thisArg?: any): (number | null)[]; }
- >[1, 2, null, 3] : (number | null)[]
- >1 : 1
-@@= skipped -9, +9 lines =@@
- >filter : { <S extends number | null>(predicate: (value: number | null, index: number, array: (number | null)[]) => value is S, thisArg?: any): S[]; (predicate: (value: number | null, index: number, array: (number | null)[]) => unknown, thisArg?: any): (number | null)[]; }
-
-   (x) => (x != null) satisfies boolean,
-->(x) => (x != null) satisfies boolean : (x: number | null) => x is number
-+>(x) => (x != null) satisfies boolean : (x: number | null) => boolean
- >x : number | null
- >(x != null) satisfies boolean : boolean
- >(x != null) : boolean
-@@= skipped -10, +10 lines =@@
- );
-
- function isEmptyString(x: unknown) {
-->isEmptyString : (x: unknown) => x is ""
-+>isEmptyString : (x: unknown) => boolean
- >x : unknown
-
-   const rv = x === "";
+   foobar.foo;