feat(material/schematics): create updateNamedImport ts migration fn

src/material/schematics/migration-utilities/typescript/import-operations.spec.ts

@@ -1,5 +1,5 @@
 import * as ts from 'typescript';
-import {updateModuleSpecifier} from './import-operations';
+import {updateModuleSpecifier, updateNamedImport} from './import-operations';
 
 describe('import operations', () => {
   describe('updateModuleSpecifier', () => {
@@ -39,6 +39,51 @@ describe('import operations', () => {
       });
     });
   });
+
+  describe('updateNamedExport', () => {
+    function runUpdateNamedExportTest(
+      description: string,
+      opts: {
+        oldFile: string;
+        newFile: string;
+        oldExport: string;
+        newExport: string;
+      },
+    ): void {
+      const node = createNode(opts.oldFile, ts.SyntaxKind.NamedImports) as ts.NamedImports;
+      const newImport = updateNamedImport(node, {
+        oldExport: opts.oldExport,
+        newExport: opts.newExport,
+      })?.updateFn(opts.oldFile);
+      expect(newImport).withContext(description).toBe(opts.newFile);
+    }
+    it('updates the named exports of import declarations', () => {
+      runUpdateNamedExportTest('named binding', {
+        oldExport: 'oldExport',
+        newExport: 'newExport',
+        oldFile: `import { oldExport } from 'module-name';`,
+        newFile: `import { newExport } from 'module-name';`,
+      });
+      runUpdateNamedExportTest('aliased named binding', {
+        oldExport: 'oldExport',
+        newExport: 'newExport',
+        oldFile: `import { oldExport as alias } from 'module-name';`,
+        newFile: `import { newExport as alias } from 'module-name';`,
+      });
+      runUpdateNamedExportTest('multiple named bindings', {
+        oldExport: 'oldExport1',
+        newExport: 'newExport1',
+        oldFile: `import { oldExport1, export2 } from 'module-name';`,
+        newFile: `import { newExport1, export2 } from 'module-name';`,
+      });
+      runUpdateNamedExportTest('multiple named bindings w/ alias', {
+        oldExport: 'oldExport2',
+        newExport: 'newExport2',
+        oldFile: `import { export1, oldExport2 as alias2 } from 'module-name';`,
+        newFile: `import { export1, newExport2 as alias2 } from 'module-name';`,
+      });
+    });
+  });
 });
 
 function createSourceFile(text: string): ts.SourceFile {

src/material/schematics/migration-utilities/typescript/import-operations.ts

@@ -21,11 +21,42 @@ export function updateModuleSpecifier(
     offset: moduleSpecifier.pos,
     updateFn: (text: string) => {
       const index = text.indexOf(moduleSpecifier.text, moduleSpecifier.pos);
-      return (
-        text.slice(0, index) +
-        opts.moduleSpecifier +
-        text.slice(index + moduleSpecifier.text.length)
-      );
+      return replaceAt(text, index, {
+        old: moduleSpecifier.text,
+        new: opts.moduleSpecifier,
+      });
     },
   };
 }
+
+/** Returns an Update that renames an export of the given named import node. */
+export function updateNamedImport(
+  node: ts.NamedImports,
+  opts: {
+    oldExport: string;
+    newExport: string;
+  },
+): Update | undefined {
+  for (let i = 0; i < node.elements.length; i++) {
+    const n = node.elements[i];
+    const name = n.propertyName ? n.propertyName : n.name;
+    if (name.escapedText === opts.oldExport) {
+      return {
+        offset: name.pos,
+        updateFn: (text: string) => {
+          const index = text.indexOf(opts.oldExport, name.pos);
+          return replaceAt(text, index, {
+            old: opts.oldExport,
+            new: opts.newExport,
+          });
+        },
+      };
+    }
+  }
+  return;
+}
+
+/** Replaces the first instance of substring.old after the given index. */
+function replaceAt(str: string, index: number, substring: {old: string; new: string}): string {
+  return str.slice(0, index) + substring.new + str.slice(index + substring.old.length);
+}