refactor(oxfmt): Rewrite --init mode in JS

apps/oxfmt/src-js/cli.ts

@@ -1,12 +1,20 @@
 import { format } from "./bindings.js";
 import { setupConfig, formatEmbeddedCode, formatFile } from "./prettier-proxy.js";
+import { runInit } from "./migration/init.js";
 
-const args = process.argv.slice(2);
+void (async () => {
+  const args = process.argv.slice(2);
 
-// Call the Rust formatter with our JS callback
-const success = await format(args, setupConfig, formatEmbeddedCode, formatFile);
+  // Handle `--init` command in JS
+  if (args.includes("--init")) {
+    return await runInit();
+  }
 
-// NOTE: It's recommended to set `process.exitCode` instead of calling `process.exit()`.
-// `process.exit()` kills the process immediately and `stdout` may not be flushed before process dies.
-// https://nodejs.org/api/process.html#processexitcode
-if (!success) process.exitCode = 1;
+  // Call the Rust formatter with our JS callback
+  const success = await format(args, setupConfig, formatEmbeddedCode, formatFile);
+
+  // NOTE: It's recommended to set `process.exitCode` instead of calling `process.exit()`.
+  // `process.exit()` kills the process immediately and `stdout` may not be flushed before process dies.
+  // https://nodejs.org/api/process.html#processexitcode
+  if (!success) process.exitCode = 1;
+})();

apps/oxfmt/src-js/migration/init.ts

@@ -0,0 +1,52 @@
+/* oxlint-disable no-console */
+
+import { stat, writeFile } from "node:fs/promises";
+
+async function isFile(path: string) {
+  try {
+    const stats = await stat(path);
+    return stats.isFile();
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Run the `--init` command to scaffold a default `.oxfmtrc.json` file.
+ */
+export async function runInit() {
+  // Check if config file already exists
+  if ((await isFile(".oxfmtrc.json")) || (await isFile(".oxfmtrc.jsonc"))) {
+    console.error("Configuration file already exists.");
+    process.exitCode = 1;
+    return;
+  }
+
+  // Build config object
+  const schemaPath = "./node_modules/oxfmt/configuration_schema.json";
+
+  const config: Record<string, unknown> = {
+    // Add `$schema` field at the top if schema file exists in `node_modules`
+    $schema: schemaPath,
+    // `ignorePatterns` is included to make visible and preferred over `.prettierignore`
+    ignorePatterns: [],
+  };
+
+  // Remove if this command is run with e.g. `npx`
+  // NOTE: To keep `$schema` field at the top, we delete it here instead of defining conditionally above
+  if (!(await isFile(schemaPath))) {
+    delete config.$schema;
+  }
+
+  try {
+    const jsonStr = JSON.stringify(config, null, 2);
+
+    // TODO: Call napi `validateConfig()` to ensure validity
+
+    await writeFile(".oxfmtrc.json", jsonStr + "\n");
+    console.log("Created `.oxfmtrc.json`.");
+  } catch {
+    console.error("Failed to write `.oxfmtrc.json`.");
+    process.exitCode = 1;
+  }
+}

apps/oxfmt/src/cli/command.rs

@@ -44,11 +44,13 @@ pub enum Mode {
     /// Default CLI mode run against files and directories
     Cli(OutputMode),
     #[cfg(feature = "napi")]
-    /// Initialize `.oxfmtrc.jsonc` with default values
-    Init,
-    #[cfg(feature = "napi")]
     /// Start language server protocol (LSP) server
     Lsp,
+    #[cfg(feature = "napi")]
+    /// Initialize `.oxfmtrc.json` with default values
+    // NOTE: This is handled by JS side before reaching Rust.
+    // Just to display help message correctly.
+    Init,
 }
 
 fn mode() -> impl bpaf::Parser<Mode> {
@@ -57,7 +59,7 @@ fn mode() -> impl bpaf::Parser<Mode> {
     #[cfg(feature = "napi")]
     {
         let init = bpaf::long("init")
-            .help("Initialize `.oxfmtrc.jsonc` with default values")
+            .help("Initialize `.oxfmtrc.json` with default values")
             .req_flag(Mode::Init)
             .hide_usage();
         let lsp = bpaf::long("lsp")

apps/oxfmt/src/cli/result.rs

@@ -5,25 +5,20 @@ pub enum CliRunResult {
     // Success
     None,
     FormatSucceeded,
-    InitSucceeded,
     // Warning error
     InvalidOptionConfig,
     FormatMismatch,
-    InitAborted,
     // Fatal error
     NoFilesFound,
     FormatFailed,
-    InitFailed,
 }
 
 impl Termination for CliRunResult {
     fn report(self) -> ExitCode {
         match self {
-            Self::None | Self::FormatSucceeded | Self::InitSucceeded => ExitCode::from(0),
-            Self::InvalidOptionConfig | Self::FormatMismatch | Self::InitAborted => {
-                ExitCode::from(1)
-            }
-            Self::NoFilesFound | Self::FormatFailed | Self::InitFailed => ExitCode::from(2),
+            Self::None | Self::FormatSucceeded => ExitCode::from(0),
+            Self::InvalidOptionConfig | Self::FormatMismatch => ExitCode::from(1),
+            Self::NoFilesFound | Self::FormatFailed => ExitCode::from(2),
         }
     }
 }

apps/oxfmt/src/lib.rs

@@ -1,6 +1,5 @@
 pub mod cli;
 mod core;
-pub mod init;
 pub mod lsp;
 
 // Only include code to run formatter when the `napi` feature is enabled.

apps/oxfmt/src/main_napi.rs

@@ -10,7 +10,6 @@ use crate::{
         CliRunResult, FormatRunner, Mode, format_command, init_miette, init_rayon, init_tracing,
     },
     core::{ExternalFormatter, JsFormatEmbeddedCb, JsFormatFileCb, JsSetupConfigCb},
-    init::run_init,
     lsp::run_lsp,
 };
 
@@ -68,7 +67,7 @@ async fn format_impl(
     };
 
     match command.mode {
-        Mode::Init => run_init(),
+        Mode::Init => unreachable!("`--init` should be handled by JS side"),
         Mode::Lsp => {
             run_lsp().await;
             CliRunResult::None

apps/oxfmt/test/init.test.ts

@@ -0,0 +1,82 @@
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import fs from "node:fs/promises";
+import { describe, expect, it } from "vitest";
+import { runCli } from "./utils";
+
+describe("init", () => {
+  it("should create .oxfmtrc.json", async () => {
+    const tempDir = await fs.mkdtemp(join(tmpdir(), "oxfmt-init-test-"));
+
+    try {
+      const result = await runCli(tempDir, ["--init"]);
+
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain("Created `.oxfmtrc.json`.");
+
+      const configPath = join(tempDir, ".oxfmtrc.json");
+      const content = await fs.readFile(configPath, "utf8");
+      const config = JSON.parse(content);
+
+      expect(config.ignorePatterns).toEqual([]);
+    } finally {
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  it("should add $schema when node_modules/oxfmt exists", async () => {
+    const tempDir = await fs.mkdtemp(join(tmpdir(), "oxfmt-init-test-"));
+
+    try {
+      // Create fake node_modules/oxfmt/configuration_schema.json
+      const schemaDir = join(tempDir, "node_modules", "oxfmt");
+      await fs.mkdir(schemaDir, { recursive: true });
+      await fs.writeFile(join(schemaDir, "configuration_schema.json"), "{}");
+
+      const result = await runCli(tempDir, ["--init"]);
+
+      expect(result.exitCode).toBe(0);
+
+      const configPath = join(tempDir, ".oxfmtrc.json");
+      const content = await fs.readFile(configPath, "utf8");
+      const config = JSON.parse(content);
+
+      expect(config.$schema).toBe("./node_modules/oxfmt/configuration_schema.json");
+      expect(Object.keys(config)[0]).toBe("$schema"); // $schema should be first
+    } finally {
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  it("should abort if .oxfmtrc.json already exists", async () => {
+    const tempDir = await fs.mkdtemp(join(tmpdir(), "oxfmt-init-test-"));
+
+    try {
+      // Create existing config file
+      await fs.writeFile(join(tempDir, ".oxfmtrc.json"), "{}");
+
+      const result = await runCli(tempDir, ["--init"]);
+
+      expect(result.exitCode).toBe(1);
+      expect(result.stderr).toContain("Configuration file already exists.");
+    } finally {
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  it("should abort if .oxfmtrc.jsonc already exists", async () => {
+    const tempDir = await fs.mkdtemp(join(tmpdir(), "oxfmt-init-test-"));
+
+    try {
+      // Create existing config file
+      await fs.writeFile(join(tempDir, ".oxfmtrc.jsonc"), "{}");
+
+      const result = await runCli(tempDir, ["--init"]);
+
+      expect(result.exitCode).toBe(1);
+      expect(result.stderr).toContain("Configuration file already exists.");
+    } finally {
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+});

apps/oxfmt/test/utils.ts

@@ -62,13 +62,13 @@ ${afterContent}
 
 // ---
 
-type RunResult = {
+export type RunResult = {
   stdout: string;
   stderr: string;
   exitCode: number;
 };
 
-async function runCli(cwd: string, args: string[]): Promise<RunResult> {
+export async function runCli(cwd: string, args: string[]): Promise<RunResult> {
   const cliPath = join(import.meta.dirname, "..", "dist", "cli.js");
 
   const result = await execa("node", [cliPath, ...args], {

tasks/website_formatter/src/snapshots/cli.snap

@@ -12,7 +12,7 @@ search: false
 
 ## Mode Options:
 - **`    --init`** — 
-  Initialize `.oxfmtrc.jsonc` with default values
+  Initialize `.oxfmtrc.json` with default values
 - **`    --lsp`** — 
   Start language server protocol (LSP) server
 

tasks/website_formatter/src/snapshots/cli_terminal.snap

@@ -5,7 +5,7 @@ expression: snapshot
 Usage: [-c=PATH] [PATH]...
 
 Mode Options:
-        --init               Initialize `.oxfmtrc.jsonc` with default values
+        --init               Initialize `.oxfmtrc.json` with default values
         --lsp                Start language server protocol (LSP) server
 
 Output Options: