Convert clang-format wrapper to a Promise-based API

cli.js

@@ -5,6 +5,7 @@ const path = require("path");
 const { program } = require("commander");
 const { clangFormatter, walk } = require("./index");
 const { STATUS } = require("./result");
+const { version } = require("./package.json");
 
 async function run(directory, cmd) {
   const dir = directory || path.resolve(".");
@@ -48,7 +49,7 @@ async function run(directory, cmd) {
   const timer = setInterval(() => {}, 100);
   try {
     program
-      .version("0.2.0")
+      .version(version)
       .description(
         `Node.js runner for LLVM clang-format
 

clang-format-spawn.js → format.js

@@ -1,11 +1,11 @@
-const process_spawn = require("child_process").spawn;
+const spawn = require("child_process").spawn;
 const fs = require("fs").promises;
 const os = require("os");
 const path = require("path");
 
 const { ko } = require("./result");
 
-async function spawn(source, done, stdio) {
+async function format(source) {
   let executable;
   if (os.platform() === "win32") {
     executable = path.resolve(__dirname, "bin", "win32", "clang-format.exe");
@@ -24,18 +24,26 @@ async function spawn(source, done, stdio) {
     if (err) {
       return Promise.reject(ko(executable, err));
     }
-    const process = process_spawn(executable, [source], { stdio: stdio });
-    process.on("close", (exitCode) => {
-      if (exitCode) {
-        done(`clang-format exited with error code ${exitCode}`);
-      } else {
-        done(null);
-      }
+    let formatted = "";
+
+    const stdio = ["ignore", "pipe", process.stderr];
+    const clangFormat = spawn(executable, [source], { stdio: stdio });
+    clangFormat.stdout.on("data", (data) => {
+      formatted += data.toString();
+    });
+
+    return new Promise((resolve, reject) => {
+      clangFormat.on("close", (exitCode) => {
+        if (exitCode) {
+          reject(ko(source, `clang-format exited with error code ${exitCode}`));
+        } else {
+          resolve(formatted);
+        }
+      });
     });
-    return Promise.resolve(process);
   } catch (err) {
     return Promise.reject(ko(null, err));
   }
 }
 
-module.exports = spawn;
+module.exports = format;

index.js

@@ -1,7 +1,7 @@
 const fs = require("fs").promises;
 const path = require("path");
 
-const clangFormatSpawn = require("./clang-format-spawn");
+const format = require("./format");
 const { ok, ko } = require("./result");
 
 const IGNORE_DIRECTORIES = Object.freeze([
@@ -63,39 +63,23 @@ async function clangFormatter(files, checkMode, sourceRoot) {
 }
 
 async function formatSource(source, relative, checkMode) {
-  return new Promise(async (resolve, reject) => {
-    let formatted = "";
-    const done = async (err) => {
-      if (err) {
-        return reject(ko(relative, err));
-      }
-      try {
-        const contents = await fs.readFile(source);
-        if (formatted.toString() === contents.toString()) {
-          resolve(ok(relative));
-        } else if (checkMode) {
-          resolve(ko(relative));
-        } else {
-          await fs.writeFile(source, formatted.toString());
-          resolve(ok(relative));
-        }
-      } catch (error) {
-        reject(ko(relative, error));
-      }
-    };
-    try {
-      const formatter = await clangFormatSpawn(source, done, [
-        "ignore",
-        "pipe",
-        process.stderr,
-      ]);
-      formatter.stdout.on("data", (data) => {
-        formatted += data.toString();
-      });
-    } catch (err) {
-      reject(err);
+  try {
+    const contents = await fs.readFile(source);
+    const formatted = await format(source);
+    if (formatted.toString() === contents.toString()) {
+      return Promise.resolve(ok(relative));
     }
-  });
+    // Contents did not match
+    if (checkMode) {
+      // check mode, so fail.
+      return Promise.resolve(ko(relative));
+    }
+    // write formatted contents to disk
+    await fs.writeFile(source, formatted.toString());
+    return Promise.resolve(ok(relative));
+  } catch (err) {
+    return Promise.reject(ko(relative, err));
+  }
 }
 
 module.exports = {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@artichoke/clang-format",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "private": true,
   "description": "Artichoke Ruby clang-format runner",
   "keywords": [