1 files changed, 70 insertions, 0 deletions
diff --git a/packages/turbo-codemod/src/transforms/create-turbo-config.ts b/packages/turbo-codemod/src/transforms/create-turbo-config.ts
new file mode 100644
index 0000000..0e8549a
--- /dev/null
+++ b/packages/turbo-codemod/src/transforms/create-turbo-config.ts
@@ -0,0 +1,70 @@
+import fs from "fs-extra";
+import path from "path";
+
+import { TransformerResults } from "../runner";
+import getTransformerHelpers from "../utils/getTransformerHelpers";
+import type { TransformerArgs } from "../types";
+
+// transformer details
+const TRANSFORMER = "create-turbo-config";
+const DESCRIPTION =
+  'Create the `turbo.json` file from an existing "turbo" key in `package.json`';
+const INTRODUCED_IN = "1.1.0";
+
+export function transformer({
+  root,
+  options,
+}: TransformerArgs): TransformerResults {
+  const { log, runner } = getTransformerHelpers({
+    transformer: TRANSFORMER,
+    rootPath: root,
+    options,
+  });
+
+  log.info(`Migrating "package.json" "turbo" key to "turbo.json" file...`);
+  const turboConfigPath = path.join(root, "turbo.json");
+  const rootPackageJsonPath = path.join(root, "package.json");
+  if (!fs.existsSync(rootPackageJsonPath)) {
+    return runner.abortTransform({
+      reason: `No package.json found at ${root}. Is the path correct?`,
+    });
+  }
+
+  // read files
+  const rootPackageJson = fs.readJsonSync(rootPackageJsonPath);
+  let rootTurboJson = null;
+  try {
+    rootTurboJson = fs.readJSONSync(turboConfigPath);
+  } catch (err) {
+    rootTurboJson = null;
+  }
+
+  // modify files
+  let transformedPackageJson = rootPackageJson;
+  let transformedTurboConfig = rootTurboJson;
+  if (!rootTurboJson && rootPackageJson["turbo"]) {
+    const { turbo: turboConfig, ...remainingPkgJson } = rootPackageJson;
+    transformedTurboConfig = turboConfig;
+    transformedPackageJson = remainingPkgJson;
+  }
+
+  runner.modifyFile({
+    filePath: turboConfigPath,
+    after: transformedTurboConfig,
+  });
+  runner.modifyFile({
+    filePath: rootPackageJsonPath,
+    after: transformedPackageJson,
+  });
+
+  return runner.finish();
+}
+
+const transformerMeta = {
+  name: `${TRANSFORMER}: ${DESCRIPTION}`,
+  value: TRANSFORMER,
+  introducedIn: INTRODUCED_IN,
+  transformer,
+};
+
+export default transformerMeta;