widen type, index signature, and add tests

Author: Arthur Ozga

src/compiler/checker.ts

@@ -84,6 +84,7 @@ namespace ts {
             getIndexTypeOfType,
             getBaseTypes,
             getBaseTypeOfLiteralType,
+            getWidenedType,
             getTypeFromTypeNode,
             getParameterType: getTypeAtPosition,
             getReturnTypeOfSignature,

src/compiler/diagnosticMessages.json

@@ -3311,7 +3311,7 @@
         "category": "Message",
         "code": 90016
     },
-    "Add index accessor for missing property '{0}'": {
+    "Add index signature for missing property '{0}'": {
         "category": "Message",
         "code": 90017
     },

src/compiler/types.ts

@@ -2383,6 +2383,7 @@
         getIndexTypeOfType(type: Type, kind: IndexKind): Type;
         getBaseTypes(type: InterfaceType): BaseType[];
         getBaseTypeOfLiteralType(type: Type): Type;
+        getWidenedType(type: Type): Type;
         getReturnTypeOfSignature(signature: Signature): Type;
         /**
          * Gets the type of a parameter at a given position in a signature.

src/services/codefixes/fixAddMissingMember.ts

@@ -37,7 +37,7 @@ namespace ts.codefix {
             const binaryExpression = token.parent.parent as BinaryExpression;
 
             const checker = context.program.getTypeChecker();
-            const widenedType = checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(binaryExpression.right));
+            const widenedType = checker.getWidenedType(checker.getBaseTypeOfLiteralType(checker.getTypeAtLocation(binaryExpression.right)));
             typeString = checker.typeToString(widenedType);
         }
 
@@ -54,7 +54,7 @@ namespace ts.codefix {
             }]
         },
         {
-            description: formatStringFromArgs(getLocaleSpecificMessage(Diagnostics.Add_index_accessor_for_missing_property_0), [token.getText()]),
+            description: formatStringFromArgs(getLocaleSpecificMessage(Diagnostics.Add_index_signature_for_missing_property_0), [token.getText()]),
             changes: [{
                 fileName: sourceFile.fileName,
                 textChanges: [{

tests/cases/fourslash/codeFixUndeclaredIndexSignatureNumericLiteral.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts' />
+
+//// [|class A {
+////     constructor() {
+////         this.x = 10;
+////     }
+//// }|]
+
+verify.rangeAfterCodeFix(`
+class A {
+    [name: string]: number;
+
+    constructor() {
+        this.x = 10;
+    }
+}
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 1);

tests/cases/fourslash/codeFixUndeclaredPropertyFunctionEmptyClass.ts

@@ -0,0 +1,20 @@
+/// <reference path='fourslash.ts' />
+
+//// [|class A {
+////     constructor() {
+////         this.x = function(x: number, y?: A){
+////             return x > 0 ? x : y;
+////         }
+////     }
+//// }|]
+
+verify.rangeAfterCodeFix(`
+class A {
+    x: (x: number, y?: A) => A;
+    constructor() {
+        this.x = function(x: number, y?: A){
+            return x > 0 ? x : y;
+        }
+    }
+}
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);

tests/cases/fourslash/codeFixUndeclaredPropertyFunctionNonEmptyClass.ts

@@ -0,0 +1,22 @@
+/// <reference path='fourslash.ts' />
+
+//// [|class A {
+////     y: number;
+////     constructor(public a: number) {
+////         this.x = function(x: number, y?: A){
+////             return x > 0 ? x : y;
+////         }
+////     }
+//// }|]
+
+verify.rangeAfterCodeFix(`
+class A {
+    x: (x: number, y?: A) => number | A;
+    y: number;
+    constructor(public a: number) {
+        this.x = function(x: number, y?: A){
+            return x > 0 ? x : y;
+        }
+    }
+}
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);

tests/cases/fourslash/codeFixUndeclaredPropertyObjectLiteral.ts

@@ -2,16 +2,18 @@
 
 //// [|class A {
 ////     constructor() {
-////         this.x = { a: 10, b: "hello" };
+////         let e: any = 10;
+////         this.x = { a: 10, b: "hello", c: undefined, d: null, e: e };
 ////     }
 //// }|]
 
 verify.rangeAfterCodeFix(`
 class A {
-    x: { a: number; b: string; };
+    x: { a: number; b: string; c: any; d: any; e: any; };
     
     constructor() {
-        this.x = { a: 10, b: "hello" };
+        let e: any = 10;
+        this.x = { a: 10, b: "hello", c: undefined, d: null, e: e };
     }
 }
-`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);

tests/cases/fourslash/codeFixUndeclaredPropertyObjectLiteralStrictNullChecks.ts

@@ -0,0 +1,21 @@
+/// <reference path='fourslash.ts' />
+
+// @strictNullChecks: true
+
+//// [|class A {
+////     constructor() {
+////         let e: any = 10;
+////         this.x = { a: 10, b: "hello", c: undefined, d: null, e: e };
+////     }
+//// }|]
+
+verify.rangeAfterCodeFix(`
+class A {
+    x: { a: number; b: string; c: undefined; d: null; e: any; };
+    
+    constructor() {
+        let e: any = 10;
+        this.x = { a: 10, b: "hello", c: undefined, d: null, e: e };
+    }
+}
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);

tests/cases/fourslash/codeFixUndeclaredPropertyThisType.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts' />
+
+//// [|class A {
+////     constructor() {
+////         this.mythis = this;
+////     }
+//// }|]
+
+verify.rangeAfterCodeFix(`
+class A {
+    mythis: this;
+
+    constructor() {
+        this.mythis = this;
+    }
+}
+`, /*includeWhiteSpace*/ false, /*errorCode*/ undefined, /*index*/ 0);