Use colours in custom terminal

Author: badsyntax

src/cli/CLI.ts

@@ -2,10 +2,11 @@ import type { ChildProcessWithoutNullStreams } from 'child_process';
 import { spawn } from 'child_process';
 
 import { getEnvConfig } from '../config/config';
+import { TerminalColors } from '../terminal/TerminalColors';
 import type { Logger } from '../util/Logger';
 
 const NEWLINE_SEPARATOR = /\r\n|\r|\n/;
-const STDOUT_PREFIX = /^[a-z]+:    /;
+const OUTPUT_PREFIX = /^([a-z]+:    )/;
 
 export class CLI {
   constructor(private readonly logger: Logger) {}
@@ -44,10 +45,25 @@ export class CLI {
       .join('\n');
   }
 
+  public static colorizeOutput(output: string): string {
+    return output
+      .split(NEWLINE_SEPARATOR)
+      .map(line => {
+        if (line.startsWith('warn:')) {
+          return (
+            line.replace(OUTPUT_PREFIX, `$1${TerminalColors.yellow}`) +
+            TerminalColors.reset
+          );
+        }
+        return line;
+      })
+      .join('\n');
+  }
+
   public static removePrefixFromStdOut(output: string): string {
     return output
       .split(NEWLINE_SEPARATOR)
-      .map(line => line.replace(STDOUT_PREFIX, ''))
+      .map(line => line.replace(OUTPUT_PREFIX, ''))
       .join('\n');
   }
 

src/terminal/Terminal.ts

@@ -3,16 +3,12 @@ import { type ChildProcessWithoutNullStreams } from 'child_process';
 
 import { EventWaiter } from '../util/EventWaiter';
 import { CLI } from '../cli/CLI';
+import { TerminalColors } from './TerminalColors';
 
 const NL = '\n';
 const CR = '\r';
 const nlRegExp = new RegExp(`${NL}([^${CR}]|$)`, 'g');
 
-class TerminalColors {
-  public static blue = '\u001b[34m';
-  public static reset = `\u001b[0m`;
-}
-
 export class Terminal implements vscode.Pseudoterminal {
   private cmd: ChildProcessWithoutNullStreams | undefined;
 
@@ -43,10 +39,10 @@ export class Terminal implements vscode.Pseudoterminal {
 
     const { cmd, output } = this.cli.exec(cmdArgs, cwd, {
       onStdOut: (buffer: string) => {
-        this.write(CLI.removePrefixFromStdOut(buffer));
+        this.write(CLI.removePrefixFromStdOut(CLI.colorizeOutput(buffer)));
       },
       onStdErr: (buffer: string) => {
-        this.write(CLI.removePrefixFromStdOut(buffer));
+        this.write(CLI.removePrefixFromStdOut(CLI.colorizeOutput(buffer)));
       },
     });
     this.cmd = cmd;

src/terminal/TerminalColors.ts

@@ -0,0 +1,5 @@
+export class TerminalColors {
+  public static blue = '\u001b[34m';
+  public static yellow = '\u001b[33m';
+  public static reset = `\u001b[0m`;
+}