fix: protect migration history before forced scaffolding

README.md

@@ -61,7 +61,7 @@ older cached version. Prisma Compute does not support Deno deployments yet.
 - `--deploy` / `--no-deploy`
 - `--workspace <id-or-name>`
 - `--yes`
-- `--force`: overwrite generated starter and Prisma files in a non-empty directory. This replaces existing Prisma config, contract, and database-client files; back up edits first.
+- `--force`: overwrite generated starter and Prisma files in a non-empty directory. This replaces existing Prisma config, contract, and database-client files; back up edits first. A non-empty standard `migrations` path is protected: use a new directory for a fresh starter, or continue working in the existing project with the Prisma CLI. Custom migration paths are not detected.
 - `--verbose`
 - `--json`
 

src/commands/create-context.ts

@@ -178,6 +178,20 @@ export const collectCreateContext = Effect.fn("Create.collectContext")(function*
     });
   }
 
+  if (force && targetPathState.exists) {
+    const migrations = yield* inspectTargetPath(path.join(targetDirectory, "migrations"));
+    if (migrations.exists && !migrations.isEmptyDirectory) {
+      const message = `Target directory ${formatPathForDisplay(targetDirectory)} contains migration history. Create a starter in a new directory, or continue working in the existing project with the Prisma CLI. --force cannot overwrite a project with existing migrations.`;
+      yield* Effect.sync(() => cancel(message, { output }));
+      return yield* new CreateFailure({
+        stage: "collect_context",
+        reason: "target_has_migrations",
+        message,
+        errorReported: true,
+      });
+    }
+  }
+
   const prismaSetupContext = yield* collectPrismaSetupContextEffect(input, {
     projectDir: targetDirectory,
     template,

src/create-outcome.ts

@@ -26,6 +26,7 @@ export const CreateFailureReasonSchema = Schema.Literals([
   "invalid_project_name",
   "target_path_not_directory",
   "target_directory_not_empty",
+  "target_has_migrations",
   "unsupported_configuration",
   "template_scaffold_failed",
   "prisma_init_failed",

src/index.ts

@@ -66,7 +66,7 @@ export const createPrismaCommand = Command.make(
     workspace: optionalString("workspace", "Prisma workspace id or name to deploy into"),
     force: optionalBoolean(
       "force",
-      "Overwrite generated starter and Prisma files in a non-empty directory",
+      "Overwrite generated starter and Prisma files; refuses a non-empty migrations path",
     ),
     yes: optionalBoolean("yes", "Skip prompts and accept default choices"),
     verbose: optionalBoolean("verbose", "Show verbose command output during setup"),

src/telemetry/create.ts

@@ -23,6 +23,7 @@ const expectedRejectionReasons = new Set<CreateFailureReason>([
   "invalid_project_name",
   "target_path_not_directory",
   "target_directory_not_empty",
+  "target_has_migrations",
   "unsupported_configuration",
   "not_authenticated",
   "workspace_missing",

tests/e2e/create-prisma.e2e.test.ts

@@ -7,6 +7,7 @@ import {
   readdir,
   realpath,
   rm,
+  stat,
   writeFile,
 } from "node:fs/promises";
 import { tmpdir } from "node:os";
@@ -264,6 +265,35 @@ describe("create-prisma e2e", () => {
         "Unrelated user file\n",
       );
       await runCommand(projectDir, ["bun", "run", "build"]);
+
+      await writeFile(contractPath, `${TEST_PSL_CONTRACT}\n// Keep this existing project edit\n`);
+      const preservedPaths = ["package.json", "prisma.config.ts", "src/prisma/contract.prisma"];
+      const migrationPaths = await readdir(path.join(projectDir, "migrations"), {
+        recursive: true,
+      });
+      for (const relativePath of migrationPaths) {
+        const filePath = path.join("migrations", relativePath);
+        if ((await stat(path.join(projectDir, filePath))).isFile()) {
+          preservedPaths.push(filePath);
+        }
+      }
+      const before = await Promise.all(
+        preservedPaths.map((filePath) => readFile(path.join(projectDir, filePath), "utf8")),
+      );
+      const completeRetry = await runCreatePrismaJson(rootDir, [...args, "--force"]);
+      expect(completeRetry.exitCode).toBe(1);
+      expect(completeRetry.result).toMatchObject({
+        ok: false,
+        error: { stage: "collect_context", message: expect.stringContaining("migration history") },
+      });
+      expect(await readdir(path.join(projectDir, "migrations"), { recursive: true })).toEqual(
+        migrationPaths,
+      );
+      expect(
+        await Promise.all(
+          preservedPaths.map((filePath) => readFile(path.join(projectDir, filePath), "utf8")),
+        ),
+      ).toEqual(before);
     },
     TEST_TIMEOUT,
   );

tests/telemetry.test.ts

@@ -84,7 +84,11 @@ describe("create telemetry", () => {
   });
 
   test("separates expected input and environment rejections from technical failures", async () => {
-    for (const reason of ["target_directory_not_empty", "workspace_missing"] as const) {
+    for (const reason of [
+      "target_directory_not_empty",
+      "target_has_migrations",
+      "workspace_missing",
+    ] as const) {
       await trackCreateFailed({
         input: createInput,
         context: createContext,
@@ -94,9 +98,10 @@ describe("create telemetry", () => {
       });
     }
     const calls = trackCliTelemetry.mock.calls as Array<[string, Record<string, unknown>]>;
-    expect(calls).toHaveLength(2);
+    expect(calls).toHaveLength(3);
     expect(calls.map(([, properties]) => properties["failure-reason"])).toEqual([
       "target_directory_not_empty",
+      "target_has_migrations",
       "workspace_missing",
     ]);
     for (const [, properties] of calls) {