From 3a20b17bf4f8df8d85f587dc9705a7d6866ec6ce Mon Sep 17 00:00:00 2001
From: Tryggvi Gylfason <tryggvi@spotify.com>
Date: Sun, 28 Jan 2024 18:58:45 +0100
Subject: [PATCH] Support tsConfig paths aliases during move operations

---
 .../src/compiler/ast/module/SourceFile.ts     | 21 +++++++++-
 .../ts-morph/src/tests/issues/1494tests.ts    | 42 +++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 packages/ts-morph/src/tests/issues/1494tests.ts

diff --git a/packages/ts-morph/src/compiler/ast/module/SourceFile.ts b/packages/ts-morph/src/compiler/ast/module/SourceFile.ts
index def51545d..ccc31b572 100644
--- a/packages/ts-morph/src/compiler/ast/module/SourceFile.ts
+++ b/packages/ts-morph/src/compiler/ast/module/SourceFile.ts
@@ -1023,7 +1023,26 @@ export class SourceFile extends SourceFileBase<ts.SourceFile> {
 
 function updateStringLiteralReferences(nodeReferences: ReadonlyArray<[StringLiteral, SourceFile]>) {
   for (const [stringLiteral, sourceFile] of nodeReferences) {
-    if (ModuleUtils.isModuleSpecifierRelative(stringLiteral.getLiteralText()))
+    const compilerOptions = stringLiteral._context.compilerOptions.get()
+    const literalText = stringLiteral.getLiteralText();
+    const paths = compilerOptions?.paths;
+    // See https://www.typescriptlang.org/docs/handbook/modules/reference.html#paths
+    if (paths) {
+      // Check if the string literal is a path alias specifier
+      for (const [path, mappings] of Object.entries(paths)) {
+        const hasWildCard = path.endsWith('*');
+        const [alias] = path.split('*');
+        if (literalText.startsWith(alias) && hasWildCard) {
+          const pathAfterAlias = FileUtils.pathJoin(
+            stringLiteral._sourceFile.getDirectoryPath(),
+            stringLiteral._sourceFile.getRelativePathAsModuleSpecifierTo(sourceFile)
+          );
+          stringLiteral.setLiteralValue(FileUtils.pathJoin(alias, pathAfterAlias));
+          break;
+        }
+      }
+    }
+    if (ModuleUtils.isModuleSpecifierRelative(literalText))
       stringLiteral.setLiteralValue(stringLiteral._sourceFile.getRelativePathAsModuleSpecifierTo(sourceFile));
   }
 }
diff --git a/packages/ts-morph/src/tests/issues/1494tests.ts b/packages/ts-morph/src/tests/issues/1494tests.ts
new file mode 100644
index 000000000..4333ba873
--- /dev/null
+++ b/packages/ts-morph/src/tests/issues/1494tests.ts
@@ -0,0 +1,42 @@
+import { ts } from "@ts-morph/common";
+import { expect } from "chai";
+import { Project } from "../../Project";
+
+describe("tests for my issue", () => {
+  it("should update specifiers with path aliases during move", () => {
+    const project = new Project({
+      useInMemoryFileSystem: true,
+      compilerOptions: {
+        baseUrl: '.',
+        paths: {
+          'Root/*': ['./*']
+        }
+      }
+    });
+
+    const fileAtRoot = project.createSourceFile("a.ts", `export function foo() {}`);
+    const fileAtNestedFolder = project.createSourceFile("nested/deep/a.ts", `export function nested() {}`);
+
+    const relImportRoot = project.createSourceFile("b.ts", `import { foo } from "./a";`);
+    const relImportFolder = project.createSourceFile("/b/b.ts", `import { foo } from "../a";`);
+
+    const aliasImport = project.createSourceFile("c.ts", `import { foo } from "Root/a";`);
+    const aliasExport = project.createSourceFile("d.ts", `export { foo } from "Root/a";`);
+    const aliasImportFolder = project.createSourceFile("/c/c.ts", `import { foo } from "Root/a";`);
+    const aliasToNestedFolder = project.createSourceFile("/d/d.ts", `import { nested } from "Root/nested/deep/a";`);
+
+
+    const dir = project.createDirectory('./a');
+    const deepDir = project.createDirectory('./nested/deep/deeper');
+    fileAtRoot.moveToDirectory(dir)
+    fileAtNestedFolder.moveToDirectory(deepDir)
+
+    expect(relImportRoot.getFullText()).to.equal(`import { foo } from "./a/a";`);
+    expect(relImportFolder.getFullText()).to.equal(`import { foo } from "../a/a";`);
+
+    expect(aliasImport.getFullText()).to.equal(`import { foo } from "Root/a/a";`);
+    expect(aliasImportFolder.getFullText()).to.equal(`import { foo } from "Root/a/a";`);
+    expect(aliasToNestedFolder.getFullText()).to.equal(`import { nested } from "Root/nested/deep/deeper/a";`);
+    expect(aliasExport.getFullText()).to.equal(`export { foo } from "Root/a/a";`);
+  });
+});