feat(terminal): restrict default allowed commands to 'ls' and 'echo'

Change the default value of `terminal.allowCommands` from an empty array to `['ls', 'echo']`. This update enhances security and focus by limiting the commands available in tutorials by default.

Lesson authors can still enable all commands by setting `terminal.allowCommands: []` explicitly in the metadata.

BREAKING CHANGE: The default value of `terminal.allowCommands` is now restricted to `['ls', 'echo']`. To allow all commands, explicitly set `terminal.allowCommands: []` in the metadata.

Closes #372

Author: RonithManikonda

packages/runtime/src/webcontainer/terminal-config.spec.ts

@@ -150,7 +150,7 @@ describe('TerminalConfig', () => {
     expect(config.panels[1].title).toBe('TERM 2');
     expect(config.panels[1].processOptions).toEqual({
       allowRedirects: true,
-      allowCommands: ['ls', 'echo'],
+      allowCommands: ['echo'],
     });
 
     expect(config.panels[2].title).toBe('OUT');
@@ -171,7 +171,7 @@ describe('TerminalConfig', () => {
     expect(config.panels[0].title).toBe('TERM 1');
     expect(config.panels[0].processOptions).toEqual({
       allowRedirects: false,
-      allowCommands: ['ls', 'echo'],
+      allowCommands: ['echo'],
     });
 
     expect(config.panels[1].title).toBe('TERM 2');

packages/runtime/src/webcontainer/terminal-config.ts

@@ -235,21 +235,21 @@ function normalizeTerminalConfig(config?: TerminalSchema): NormalizedTerminalCon
 
   const panels: TerminalPanel[] = [];
 
-  const resolveAllowCommands = (allowCommands?: string[]): string[] | undefined => {
-    if (allowCommands === undefined) {
-      return DEFAULT_COMMANDS;
+  const resolveAllowCommands = (globalCommands?: string[], panelCommands?: string[]): string[] | undefined => {
+    if (panelCommands === undefined) {
+      return globalCommands ?? DEFAULT_COMMANDS;
     }
 
-    if (Array.isArray(allowCommands) && allowCommands.length === 0) {
+    if (Array.isArray(panelCommands) && panelCommands.length === 0) {
       return undefined;
     }
 
-    return allowCommands;
+    return panelCommands;
   };
 
   const options = {
     allowRedirects: config.allowRedirects,
-    allowCommands: resolveAllowCommands(config.allowCommands),
+    allowCommands: config.allowCommands,
   };
 
   if (config.panels) {
@@ -273,7 +273,7 @@ function normalizeTerminalConfig(config?: TerminalSchema): NormalizedTerminalCon
             id: panel.id,
             title: panel.title,
             allowRedirects: panel.allowRedirects ?? config.allowRedirects,
-            allowCommands: panel.allowCommands ? resolveAllowCommands(panel.allowCommands) : options.allowCommands,
+            allowCommands: resolveAllowCommands(config.allowCommands, panel.allowCommands),
           });
         }