Partial Types (microsoft#11233)

Author: RyanCavanaugh

src/compiler/checker.ts

@@ -4475,6 +4475,8 @@ namespace ts {
                     }
                     else if ((<ObjectType>type).objectFlags & ObjectFlags.Anonymous) {
                         resolveAnonymousTypeMembers(<AnonymousType>type);
+                    } else if ((<ObjectType>type).objectFlags & ObjectFlags.Partial) {
+                        resolvePartialTypeMembers(<PartialType>type);
                     }
                     else if ((<ObjectType>type).flags & TypeFlags.Partial) {
                     resolvePartialTypeMembers(<PartialType>type);
@@ -5753,6 +5755,7 @@ namespace ts {
             return links.resolvedType;
         }
 
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
 <<<<<<< 7b34b612beda66b0812462a3feeabc63852cd842
         function getIndexTypeForTypeParameter(type: TypeParameter) {
             if (!type.resolvedIndexType) {
@@ -5903,6 +5906,14 @@ namespace ts {
             return links.resolvedType;
         }
 
+        function getTypeFromPartialTypeNode(node: PartialTypeNode): Type {
+            const links = getNodeLinks(node);
+            if (!links.resolvedType) {
+                links.resolvedType = getPartialType(getTypeOfNode(node.type));
+            }
+            return links.resolvedType;
+        }
+
         function getPartialType(type: Type): Type {
             if (type.resolvedPartialType) {
                 return type.resolvedPartialType;

src/compiler/types.ts

@@ -887,6 +887,7 @@ namespace ts {
         type: TypeNode;
     }
 
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
     export interface TypeOperatorNode extends TypeNode {
         kind: SyntaxKind.TypeOperator;
         operator: SyntaxKind.KeyOfKeyword;
@@ -899,6 +900,14 @@ namespace ts {
         indexType: TypeNode;
     }
 
+=======
+    // @kind(SyntaxKind.PartialType)
+    export interface PartialTypeNode extends TypeNode {
+        type: TypeNode;
+    }
+
+    // @kind(SyntaxKind.StringLiteralType)
+>>>>>>> Partial Types (#11233)
     export interface LiteralTypeNode extends TypeNode {
         kind: SyntaxKind.LiteralType;
         literal: Expression;
@@ -2692,8 +2701,8 @@ namespace ts {
         /* @internal */
         ContainsObjectLiteral   = 1 << 22,  // Type is or contains object literal type
         /* @internal */
-        ContainsAnyFunctionType = 1 << 23,  // Type is or contains object literal type
-        Partial                 = 1 << 24,  // Partial type
+        ContainsAnyFunctionType = 1 << 21,  // Type is or contains object literal type
+        Partial                 = 1 << 22,  // Partial type
 
         /* @internal */
         Nullable = Undefined | Null,

tests/baselines/reference/partialType2.errors.txt

@@ -1,21 +1,43 @@
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
 tests/cases/compiler/partialType2.ts(10,5): error TS2322: Type 'partial T' is not assignable to type 'T'.
+=======
+tests/cases/compiler/partialType2.ts(8,12): error TS2304: Cannot find name 'subset'.
+tests/cases/compiler/partialType2.ts(8,19): error TS1005: '=' expected.
+tests/cases/compiler/partialType2.ts(8,19): error TS2693: 'T' only refers to a type, but is being used as a value here.
+>>>>>>> Partial Types (#11233)
 tests/cases/compiler/partialType2.ts(16,5): error TS2322: Type '{ name: string; length: number; foo: number; }' is not assignable to type 'partial T'.
 tests/cases/compiler/partialType2.ts(18,11): error TS2339: Property 'name' does not exist on type 'partial T'.
 
 
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
 ==== tests/cases/compiler/partialType2.ts (3 errors) ====
+=======
+==== tests/cases/compiler/partialType2.ts (5 errors) ====
+>>>>>>> Partial Types (#11233)
     interface State {
         name: string;
         length: number;
         foo?: number;
     }
 
     function doSomething1<T>(x: T) {
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
         let y: partial T = <any>null;
         y = x; // Should be OK
         x = y; // Error
         ~
 !!! error TS2322: Type 'partial T' is not assignable to type 'T'.
+=======
+        let y: subset T = <any>null;
+               ~~~~~~
+!!! error TS2304: Cannot find name 'subset'.
+                      ~
+!!! error TS1005: '=' expected.
+                      ~
+!!! error TS2693: 'T' only refers to a type, but is being used as a value here.
+        y = x; // Should be OK
+        x = y; // Error
+>>>>>>> Partial Types (#11233)
     }
 
     function doSomething2<T extends State>(x: T) {

tests/baselines/reference/partialType2.js

@@ -6,7 +6,11 @@ interface State {
 }
 
 function doSomething1<T>(x: T) {
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
     let y: partial T = <any>null;
+=======
+    let y: subset T = <any>null;
+>>>>>>> Partial Types (#11233)
     y = x; // Should be OK
     x = y; // Error
 }
@@ -28,7 +32,11 @@ function doSomething2<T extends State>(x: T) {
 
 //// [partialType2.js]
 function doSomething1(x) {
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
     var y = null;
+=======
+    var y = T = null;
+>>>>>>> Partial Types (#11233)
     y = x; // Should be OK
     x = y; // Error
 }

tests/baselines/reference/partialType4.js

@@ -27,6 +27,7 @@ subs.name = false; // not ok
 // Errors
 subs['err'] = false;
 subs[12] = false;
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
 
 
 //// [partialType4.d.ts]
@@ -36,3 +37,5 @@ interface State1 {
     [key: string]: string | number;
 }
 declare const subs: partial State1;
+=======
+>>>>>>> Partial Types (#11233)

tests/cases/compiler/partialType2.ts

@@ -5,7 +5,11 @@ interface State {
 }
 
 function doSomething1<T>(x: T) {
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
     let y: partial T = <any>null;
+=======
+    let y: subset T = <any>null;
+>>>>>>> Partial Types (#11233)
     y = x; // Should be OK
     x = y; // Error
 }

tests/cases/compiler/partialType4.ts

@@ -1,5 +1,8 @@
 // @strictNullChecks: true
+<<<<<<< d147616ccc57b7c9f6418074c8edffd3ee258961
 // @declaration: true
+=======
+>>>>>>> Partial Types (#11233)
 
 interface State1 {
     name: string;