Handle repeated bindExpression and bindImport calls

__tests__/tests.ts

@@ -690,6 +690,37 @@ describe('htmlbars-inline-precompile', function () {
       expect(transformed).toContain(`import two from "my-library"`);
     });
 
+    it('reuses existing imports when possible', () => {
+      precompile = runASTTransform(compiler, importTransform);
+
+      let transformed = transform(stripIndent`
+        import { precompileTemplate } from '@ember/template-compilation';
+        export default function() {
+          const template = precompileTemplate('{{onePlusOne}}{{onePlusOne}}');
+        }
+      `);
+
+      expect(transformed).toContain(`{{two}}{{two}}`);
+      expect(transformed).toContain(`locals: [two]`);
+      expect(transformed).toContain(`import two from "my-library"`);
+    });
+
+    it('rebinds existing imports when necessary', () => {
+      precompile = runASTTransform(compiler, importTransform);
+
+      let transformed = transform(stripIndent`
+        import { precompileTemplate } from '@ember/template-compilation';
+        export default function() {
+          const template = precompileTemplate('{{onePlusOne}}{{#let "twice" as |two|}}{{onePlusOne}}{{/let}}');
+        }
+      `);
+
+      expect(transformed).toContain(`{{two}}{{#let "twice" as |two|}}{{two0}}{{/let}}`);
+      expect(transformed).toContain(`locals: [two, two0]`);
+      expect(transformed).toContain(`import two from "my-library"`);
+      expect(transformed).toContain('let two0 = two');
+    });
+
     it('does not smash existing js binding for expression', function () {
       precompile = runASTTransform(compiler, expressionTransform);
 
@@ -751,6 +782,22 @@ describe('htmlbars-inline-precompile', function () {
       expect(transformed).toContain(`let two = 1 + 1`);
     });
 
+    it('does not smash other previously-bound expressions with new ones', () => {
+      precompile = runASTTransform(compiler, expressionTransform);
+
+      let transformed = transform(stripIndent`
+        import { precompileTemplate } from '@ember/template-compilation';
+        export default function() {
+          const template = precompileTemplate('{{onePlusOne}}{{onePlusOne}}');
+        }
+      `);
+
+      expect(transformed).toContain(`{{two}}{{two0}}`);
+      expect(transformed).toContain(`locals: [two, two0]`);
+      expect(transformed).toContain(`let two = 1 + 1`);
+      expect(transformed).toContain(`let two0 = 1 + 1`);
+    });
+
     it('can bind expressions that need imports', function () {
       let nowTransform: ASTPluginBuilder<WithJSUtils<ASTPluginEnvironment>> = (env) => {
         return {

src/js-utils.ts

@@ -50,7 +50,9 @@ export class JSUtils {
     let name = unusedNameLike(
       opts?.nameHint ?? 'a',
       (candidate) =>
-        this.#template.scope.hasBinding(candidate) || astNodeHasBinding(target, candidate)
+        this.#template.scope.hasBinding(candidate) ||
+        this.#locals.includes(candidate) ||
+        astNodeHasBinding(target, candidate)
     );
     let t = this.#babel.types;
     this.#emitStatement(
@@ -98,8 +100,19 @@ export class JSUtils {
       opts?.nameHint
     );
 
-    let identifier = unusedNameLike(importedIdentifier.name, (candidate) =>
-      astNodeHasBinding(target, candidate)
+    // If we're already referencing the imported name from the outer scope and
+    // it's not shadowed at our target location in the template, we can reuse
+    // the existing import.
+    if (
+      this.#locals.includes(importedIdentifier.name) &&
+      !astNodeHasBinding(target, importedIdentifier.name)
+    ) {
+      return importedIdentifier.name;
+    }
+
+    let identifier = unusedNameLike(
+      importedIdentifier.name,
+      (candidate) => this.#locals.includes(candidate) || astNodeHasBinding(target, candidate)
     );
     if (identifier !== importedIdentifier.name) {
       // The importedIdentifier that we have in Javascript is not usable within