Quick fix to correct qualified names to indexed access types

src/compiler/diagnosticMessages.json

@@ -3657,6 +3657,10 @@
         "category": "Message",
         "code": 90025
     },
+    "Rewrite as the indexed access type '{0}'.": {
+        "category": "Message",
+        "code": 90026
+    },
 
     "Convert function to an ES2015 class": {
         "category": "Message",

src/services/codefixes/correctQualifiedNameToIndexedAccessType.ts

@@ -0,0 +1,27 @@
+/* @internal */
+namespace ts.codefix {
+    registerCodeFix({
+        errorCodes: [Diagnostics.Cannot_access_0_1_because_0_is_a_type_but_not_a_namespace_Did_you_mean_to_retrieve_the_type_of_the_property_1_in_0_with_0_1.code],
+        getCodeActions: (context: CodeFixContext) => {
+            const sourceFile = context.sourceFile;
+            const token = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false);
+            const qualifiedName = getAncestor(token, SyntaxKind.QualifiedName) as QualifiedName;
+            Debug.assert(!!qualifiedName, "Expected position to be owned by a qualified name.");
+            if (!isIdentifier(qualifiedName.left)) {
+                return undefined;
+            }
+            const leftText = qualifiedName.left.getText(sourceFile);
+            const rightText = qualifiedName.right.getText(sourceFile);
+            const replacement = createIndexedAccessTypeNode(
+                createTypeReferenceNode(qualifiedName.left, /*typeArguments*/ undefined),
+                createLiteralTypeNode(createLiteral(rightText)));
+            const changeTracker = textChanges.ChangeTracker.fromCodeFixContext(context);
+            changeTracker.replaceNode(sourceFile, qualifiedName, replacement);
+
+            return [{
+                description: formatStringFromArgs(getLocaleSpecificMessage(Diagnostics.Rewrite_as_the_indexed_access_type_0), [`${leftText}["${rightText}"]`]),
+                changes: changeTracker.getChanges()
+            }];
+        }
+    });
+}

src/services/codefixes/fixes.ts

@@ -1,3 +1,4 @@
+/// <reference path="correctQualifiedNameToIndexedAccessType.ts" />
 /// <reference path="fixClassIncorrectlyImplementsInterface.ts" />
 /// <reference path="fixAddMissingMember.ts" />
 /// <reference path="fixSpelling.ts" />

tests/cases/fourslash/codeFixReplaceQualifiedNameWithIndexedAccessType01.ts

@@ -0,0 +1,8 @@
+/// <reference path='fourslash.ts' />
+
+//// export interface Foo {
+////   bar: string;
+//// }
+//// const x: [|Foo.bar|] = ""
+
+verify.rangeAfterCodeFix(`Foo["bar"]`);