feat(commands): Implement argument handling for custom commands via a prompt pipeline (#4702)

packages/cli/src/ui/commands/types.ts

@@ -14,6 +14,15 @@ import { SessionStatsState } from '../contexts/SessionContext.js';
 
 // Grouped dependencies for clarity and easier mocking
 export interface CommandContext {
+  // Invocation properties for when commands are called.
+  invocation?: {
+    /** The raw, untrimmed input string from the user. */
+    raw: string;
+    /** The primary name of the command that was matched. */
+    name: string;
+    /** The arguments string that follows the command name. */
+    args: string;
+  };
   // Core services and configuration
   services: {
     // TODO(abhipatel12): Ensure that config is never null.
@@ -132,7 +141,7 @@ export interface SlashCommand {
   // The action to run. Optional for parent commands that only group sub-commands.
   action?: (
     context: CommandContext,
-    args: string,
+    args: string, // TODO: Remove args. CommandContext now contains the complete invocation.
   ) =>
     | void
     | SlashCommandActionReturn

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -238,7 +238,18 @@ export const useSlashCommandProcessor = (
         const args = parts.slice(pathIndex).join(' ');
 
         if (commandToExecute.action) {
-          const result = await commandToExecute.action(commandContext, args);
+          const fullCommandContext: CommandContext = {
+            ...commandContext,
+            invocation: {
+              raw: trimmed,
+              name: commandToExecute.name,
+              args,
+            },
+          };
+          const result = await commandToExecute.action(
+            fullCommandContext,
+            args,
+          );
 
           if (result) {
             switch (result.type) {
@@ -288,9 +299,9 @@ export const useSlashCommandProcessor = (
                 await config
                   ?.getGeminiClient()
                   ?.setHistory(result.clientHistory);
-                commandContext.ui.clear();
+                fullCommandContext.ui.clear();
                 result.history.forEach((item, index) => {
-                  commandContext.ui.addItem(item, index);
+                  fullCommandContext.ui.addItem(item, index);
                 });
                 return { type: 'handled' };
               }