chore: Refactor HtmlBeautifier class and improve error handling

Author: aliariff

src/formatter/htmlbeautifier.ts

@@ -3,34 +3,39 @@ import * as cp from "child_process";
 const isWsl = require("is-wsl");
 
 export default class HtmlBeautifier {
+  private logChannel: vscode.LogOutputChannel;
+
+  constructor() {
+    this.logChannel = vscode.window.createOutputChannel("ERB Beautifier", {
+      log: true,
+    });
+  }
+
   /**
-   * Formats the given input using HTML Beautifier
-   * @param {string} input - The input to be formatted
-   * @returns {Promise<string>} The formatted input
+   * Formats the input string using HTML Beautifier.
+   * @param input The input string to be formatted.
+   * @returns A promise that resolves to the formatted string.
    */
   public async format(input: string): Promise<string> {
     try {
-      const cmd = `${this.exe} ${this.cliOptions.join(
-        " "
-      )} with custom env ${JSON.stringify(this.customEnvVars)}`;
-      console.log(`Formatting ERB with command: ${cmd}`);
-      console.time(cmd);
-
+      const startTime = Date.now();
       const result = await this.executeCommand(input);
-
-      console.timeEnd(cmd);
+      const duration = Date.now() - startTime;
+      this.logChannel.info(
+        `Formatting completed successfully in ${duration}ms.`
+      );
       return result;
     } catch (error) {
-      console.error(error);
-      const errorMessage =
-        error instanceof Error ? error.message : "Unknown error occurred";
-      vscode.window.showErrorMessage(
-        `Error occurred while formatting: ${errorMessage}`
-      );
+      this.handleError(error, "Error occurred while formatting");
       throw error;
     }
   }
 
+  /**
+   * Executes the formatting command with the provided input.
+   * @param input The input to format.
+   * @returns A promise that resolves to the formatted output.
+   */
   private executeCommand(input: string): Promise<string> {
     return new Promise((resolve, reject) => {
       // Handle spawn EINVAL error on Windows. See https://github.com/nodejs/node/issues/52554
@@ -44,53 +49,37 @@ export default class HtmlBeautifier {
         ...shellOptions,
       });
 
-      if (htmlbeautifier.stdin === null || htmlbeautifier.stdout === null) {
-        const msg = "Couldn't initialize STDIN or STDOUT";
-        console.warn(msg);
-        vscode.window.showErrorMessage(msg);
-        reject(new Error(msg));
-        return;
-      }
-
-      let formattedResult = "";
-      let errorMessage = "";
-      let stdoutChunks: Buffer[] = [];
-      let stderrChunks: Buffer[] = [];
+      const fullCommand = `${this.exe} ${this.cliOptions.join(" ")} (cwd: ${
+        vscode.workspace.rootPath || __dirname
+      }) with custom env: ${JSON.stringify(this.customEnvVars)}`;
+      this.logChannel.info(`Formatting ERB with command: ${fullCommand}`);
 
-      htmlbeautifier.on("error", (err) => {
-        console.warn(err);
-        vscode.window.showErrorMessage(
-          `Couldn't run ${this.exe} '${err.message}'`
+      if (!htmlbeautifier.stdin || !htmlbeautifier.stdout) {
+        return this.handleSpawnError(
+          reject,
+          "Couldn't initialize STDIN or STDOUT"
         );
-        reject(err);
-      });
-
-      htmlbeautifier.stdout.on("data", (chunk) => {
-        stdoutChunks.push(chunk);
-      });
+      }
 
-      htmlbeautifier.stdout.on("end", () => {
-        let result = Buffer.concat(stdoutChunks).toString();
-        formattedResult = this.handleFinalNewline(input, result);
-      });
+      const stdoutChunks: Buffer[] = [];
+      const stderrChunks: Buffer[] = [];
 
-      htmlbeautifier.stderr.on("data", (chunk) => {
-        stderrChunks.push(chunk);
-      });
+      htmlbeautifier.stdout.on("data", (chunk) => stdoutChunks.push(chunk));
+      htmlbeautifier.stderr.on("data", (chunk) => stderrChunks.push(chunk));
 
-      htmlbeautifier.stderr.on("end", () => {
-        errorMessage = Buffer.concat(stderrChunks).toString();
-      });
+      htmlbeautifier.on("error", (err) =>
+        this.handleSpawnError(
+          reject,
+          `Couldn't run ${this.exe}: ${err.message}`,
+          err
+        )
+      );
 
       htmlbeautifier.on("exit", (code) => {
-        if (code) {
-          vscode.window.showErrorMessage(
-            `Failed with exit code: ${code}. '${errorMessage}'`
-          );
-          reject(new Error(`Command failed with exit code ${code}`));
-        } else {
-          resolve(formattedResult);
-        }
+        const formattedResult = Buffer.concat(stdoutChunks).toString();
+        const finalResult = this.handleFinalNewline(input, formattedResult);
+        const errorMessage = Buffer.concat(stderrChunks).toString();
+        this.handleExit(code, finalResult, errorMessage, resolve, reject);
       });
 
       htmlbeautifier.stdin.write(input);
@@ -99,8 +88,64 @@ export default class HtmlBeautifier {
   }
 
   /**
-   * Returns the executable path for HTML Beautifier
-   * @returns {string} The executable path
+   * Handles errors during process spawning.
+   * @param reject The promise reject function.
+   * @param message The error message to log and show to the user.
+   * @param err Optional error object.
+   */
+  private handleSpawnError(
+    reject: (reason?: any) => void,
+    message: string,
+    err?: Error
+  ): void {
+    this.logChannel.warn(message);
+    vscode.window.showErrorMessage(message);
+    if (err) {
+      this.logChannel.warn(err.message);
+    }
+    reject(err || new Error(message));
+  }
+
+  /**
+   * Handles the process exit event and resolves or rejects the promise.
+   * @param code The process exit code.
+   * @param result The formatted result.
+   * @param errorMessage The error message, if any.
+   * @param resolve The promise resolve function.
+   * @param reject The promise reject function.
+   */
+  private handleExit(
+    code: number | null,
+    result: string,
+    errorMessage: string,
+    resolve: (value: string | PromiseLike<string>) => void,
+    reject: (reason?: any) => void
+  ): void {
+    if (code && code !== 0) {
+      const error = `Failed with exit code: ${code}. ${errorMessage}`;
+      this.logChannel.error(error);
+      vscode.window.showErrorMessage(error);
+      reject(new Error(error));
+    } else {
+      resolve(result);
+    }
+  }
+
+  /**
+   * Handles errors by logging and displaying a message to the user.
+   * @param error The error object or message.
+   * @param userMessage The message to display to the user.
+   */
+  private handleError(error: any, userMessage: string): void {
+    const errorMessage =
+      error instanceof Error ? error.message : "Unknown error occurred";
+    this.logChannel.error(errorMessage);
+    vscode.window.showErrorMessage(`${userMessage}: ${errorMessage}`);
+  }
+
+  /**
+   * Gets the executable path for HTML Beautifier based on the configuration.
+   * @returns The path to the executable.
    */
   private get exe(): string {
     const config = vscode.workspace.getConfiguration("vscode-erb-beautify");
@@ -112,26 +157,26 @@ export default class HtmlBeautifier {
   }
 
   /**
-   * Determines if the current platform is Windows (excluding WSL)
-   * @returns {boolean} True if the platform is Windows, false otherwise
+   * Checks if the current platform is Windows (excluding WSL).
+   * @returns True if the platform is Windows; false otherwise.
    */
   private isWindows(): boolean {
     return process.platform === "win32" && !isWsl;
   }
 
   /**
-   * Returns the command-line options for HTML Beautifier
-   * @returns {string[]} The command-line options
+   * Retrieves the command-line options for HTML Beautifier from the configuration.
+   * @returns An array of command-line options.
    */
   private get cliOptions(): string[] {
     const config = vscode.workspace.getConfiguration("vscode-erb-beautify");
-    const acc: string[] = [];
+    const options: string[] = [];
 
     if (config.get("useBundler")) {
-      acc.push("exec", "htmlbeautifier");
+      options.push("exec", "htmlbeautifier");
     }
 
-    return Object.keys(config).reduce(function (acc, key) {
+    return Object.keys(config).reduce((acc, key) => {
       switch (key) {
         case "indentBy":
           acc.push("--indent-by", config[key]);
@@ -154,35 +199,31 @@ export default class HtmlBeautifier {
           break;
       }
       return acc;
-    }, acc);
+    }, options);
   }
 
   /**
-   * Retrieves the custom environment variables from the configuration
-   * @returns {Record<string, string>} The custom environment variables
+   * Retrieves custom environment variables from the configuration.
+   * @returns A record of custom environment variables.
    */
   private get customEnvVars(): Record<string, string> {
     const config = vscode.workspace.getConfiguration("vscode-erb-beautify");
-    const customEnvVar = config.get("customEnvVar", {}) as Record<
-      string,
-      string
-    >;
-    return customEnvVar;
+    return config.get("customEnvVar", {}) as Record<string, string>;
   }
 
   /**
-   * Adjusts the final newline of the result string based on the VS Code configuration and the input string.
-   * @param {string} input - The original input string.
-   * @param {string} result - The result string to be processed.
-   * @returns {string} The processed result string.
+   * Adjusts the final newline of the result string based on VS Code configuration.
+   * @param input The original input string.
+   * @param result The formatted result string.
+   * @returns The adjusted result string.
    */
   private handleFinalNewline(input: string, result: string): string {
     // Get the 'insertFinalNewline' setting from VS Code configuration
     const insertFinalNewline = vscode.workspace
       .getConfiguration()
       .get("files.insertFinalNewline");
 
-    // Check if the result string ends with a newline
+    // Determine if the result ends with a newline
     const resultEndsWithNewline =
       result.endsWith("\n") || result.endsWith("\r\n");
 
@@ -191,11 +232,8 @@ export default class HtmlBeautifier {
       // Get the 'files.eol' setting from VS Code configuration
       const eol = vscode.workspace.getConfiguration().get("files.eol");
 
-      // Set the newline character(s) based on the 'files.eol' setting and the platform
-      let newline = eol;
-      if (eol === "auto") {
-        newline = this.isWindows() ? "\r\n" : "\n";
-      }
+      // Determine newline character(s) based on the 'files.eol' setting and the platform
+      let newline = eol === "auto" ? (this.isWindows() ? "\r\n" : "\n") : eol;
 
       // Append the newline to the result
       result += newline;
@@ -208,11 +246,8 @@ export default class HtmlBeautifier {
 
       // If the input and result use different newline character(s)
       if (inputNewline !== resultNewline) {
-        // Remove the newline from the end of the result
-        result = result.slice(0, -resultNewline.length);
-
-        // Append the newline from the input to the result
-        result += inputNewline;
+        // Remove the newline from the end of the result and append the input's newline
+        result = result.slice(0, -resultNewline.length) + inputNewline;
       }
     }
 
@@ -221,20 +256,16 @@ export default class HtmlBeautifier {
   }
 
   /**
-   * Determines the type of newline used in the input string.
-   * @param {string} input - The input string.
-   * @returns {string} The newline character(s) used in the input string, or an empty string if the input does not end with a newline.
+   * Determines the newline character(s) used in the input string.
+   * @param input The input string.
+   * @returns The newline character(s) used, or an empty string if none.
    */
   private getNewline(input: string): string {
-    // If the input ends with a Windows-style newline, return '\r\n'
     if (input.endsWith("\r\n")) {
-      return "\r\n";
-    }
-    // If the input ends with a Unix-style newline, return '\n'
-    else if (input.endsWith("\n")) {
-      return "\n";
+      return "\r\n"; // Return Windows-style newline
+    } else if (input.endsWith("\n")) {
+      return "\n"; // Return Unix-style newline
     }
-    // If the input does not end with a newline, return an empty string
-    return "";
+    return ""; // Return empty if no newline found
   }
 }