Fix assertion -- an import may come from a require() call (#19667)

* Fix assertion -- an import may come from a require() call

* Add test for `import("./a")`

src/services/codefixes/importFixes.ts

@@ -237,12 +237,12 @@ namespace ts.codefix {
                 return parent as ImportDeclaration;
             case SyntaxKind.ExternalModuleReference:
                 return (parent as ExternalModuleReference).parent;
-            case SyntaxKind.ImportEqualsDeclaration:
-                return parent as ImportEqualsDeclaration;
-            default:
-                Debug.assert(parent.kind === SyntaxKind.ExportDeclaration);
+            case SyntaxKind.ExportDeclaration:
+            case SyntaxKind.CallExpression: // For "require()" calls
                 // Ignore these, can't add imports to them.
                 return undefined;
+            default:
+                Debug.fail();
         }
     }
 

tests/cases/fourslash/completionsImport_require.ts

@@ -0,0 +1,42 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+
+// @Filename: /a.ts
+////export const foo = 0;
+
+// @Filename: /b.js
+////const a = require("./a");
+////fo/*b*/
+
+// @Filename: /c.js
+////const a = import("./a");
+////fo/*c*/
+
+goTo.marker("b");
+verify.completionListContains({ name: "foo", source: "/a" }, "const foo: 0", "", "const", /*spanIndex*/ undefined, /*hasAction*/ true, { includeExternalModuleExports: true });
+
+verify.applyCodeActionFromCompletion("b", {
+    name: "foo",
+    source: "/a",
+    description: `Import 'foo' from "./a".`,
+    // TODO: GH#18445
+    newFileContent: `import { foo } from "./a";\r
+\r
+const a = require("./a");
+fo`,
+});
+
+goTo.marker("c");
+verify.completionListContains({ name: "foo", source: "/a" }, "const foo: 0", "", "const", /*spanIndex*/ undefined, /*hasAction*/ true, { includeExternalModuleExports: true });
+
+verify.applyCodeActionFromCompletion("c", {
+    name: "foo",
+    source: "/a",
+    description: `Import 'foo' from "./a".`,
+    // TODO: GH#18445
+    newFileContent: `import { foo } from "./a";\r
+\r
+const a = import("./a");
+fo`,
+});