Add auto-slash-command hook for intercepting and replacing slash commands

This hook intercepts user messages starting with '/' and REPLACES them with the actual command template output instead of injecting instructions. The implementation includes:

- Slash command detection (detector.ts) - identifies messages starting with '/'
- Command discovery and execution (executor.ts) - loads templates from ~/.claude/commands/ or similar
- Hook integration (index.ts) - registers with chat.message event to replace output.parts
- Comprehensive test coverage - 37 tests covering detection, replacement, error handling, and command exclusions
- Configuration support in HookNameSchema

Key features:
- Supports excluded commands to skip processing
- Loads command templates from user's command directory
- Replaces user input before reaching the LLM
- Tests all edge cases including missing files, malformed templates, and special commands

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/auto-slash-command/executor.ts

@@ -0,0 +1,193 @@
+import { existsSync, readdirSync, readFileSync } from "fs"
+import { join, basename, dirname } from "path"
+import { homedir } from "os"
+import {
+  parseFrontmatter,
+  resolveCommandsInText,
+  resolveFileReferencesInText,
+  sanitizeModelField,
+  getClaudeConfigDir,
+} from "../../shared"
+import { isMarkdownFile } from "../../shared/file-utils"
+import { discoverAllSkills, type LoadedSkill } from "../../features/opencode-skill-loader"
+import type { ParsedSlashCommand } from "./types"
+
+interface CommandScope {
+  type: "user" | "project" | "opencode" | "opencode-project" | "skill"
+}
+
+interface CommandMetadata {
+  name: string
+  description: string
+  argumentHint?: string
+  model?: string
+  agent?: string
+  subtask?: boolean
+}
+
+interface CommandInfo {
+  name: string
+  path?: string
+  metadata: CommandMetadata
+  content?: string
+  scope: CommandScope["type"]
+}
+
+function discoverCommandsFromDir(commandsDir: string, scope: CommandScope["type"]): CommandInfo[] {
+  if (!existsSync(commandsDir)) {
+    return []
+  }
+
+  const entries = readdirSync(commandsDir, { withFileTypes: true })
+  const commands: CommandInfo[] = []
+
+  for (const entry of entries) {
+    if (!isMarkdownFile(entry)) continue
+
+    const commandPath = join(commandsDir, entry.name)
+    const commandName = basename(entry.name, ".md")
+
+    try {
+      const content = readFileSync(commandPath, "utf-8")
+      const { data, body } = parseFrontmatter(content)
+
+      const isOpencodeSource = scope === "opencode" || scope === "opencode-project"
+      const metadata: CommandMetadata = {
+        name: commandName,
+        description: data.description || "",
+        argumentHint: data["argument-hint"],
+        model: sanitizeModelField(data.model, isOpencodeSource ? "opencode" : "claude-code"),
+        agent: data.agent,
+        subtask: Boolean(data.subtask),
+      }
+
+      commands.push({
+        name: commandName,
+        path: commandPath,
+        metadata,
+        content: body,
+        scope,
+      })
+    } catch {
+      continue
+    }
+  }
+
+  return commands
+}
+
+function skillToCommandInfo(skill: LoadedSkill): CommandInfo {
+  return {
+    name: skill.name,
+    path: skill.path,
+    metadata: {
+      name: skill.name,
+      description: skill.definition.description || "",
+      argumentHint: skill.definition.argumentHint,
+      model: skill.definition.model,
+      agent: skill.definition.agent,
+      subtask: skill.definition.subtask,
+    },
+    content: skill.definition.template,
+    scope: "skill",
+  }
+}
+
+function discoverAllCommands(): CommandInfo[] {
+  const userCommandsDir = join(getClaudeConfigDir(), "commands")
+  const projectCommandsDir = join(process.cwd(), ".claude", "commands")
+  const opencodeGlobalDir = join(homedir(), ".config", "opencode", "command")
+  const opencodeProjectDir = join(process.cwd(), ".opencode", "command")
+
+  const userCommands = discoverCommandsFromDir(userCommandsDir, "user")
+  const opencodeGlobalCommands = discoverCommandsFromDir(opencodeGlobalDir, "opencode")
+  const projectCommands = discoverCommandsFromDir(projectCommandsDir, "project")
+  const opencodeProjectCommands = discoverCommandsFromDir(opencodeProjectDir, "opencode-project")
+
+  const skills = discoverAllSkills()
+  const skillCommands = skills.map(skillToCommandInfo)
+
+  return [
+    ...opencodeProjectCommands,
+    ...projectCommands,
+    ...opencodeGlobalCommands,
+    ...userCommands,
+    ...skillCommands,
+  ]
+}
+
+function findCommand(commandName: string): CommandInfo | null {
+  const allCommands = discoverAllCommands()
+  return allCommands.find(
+    (cmd) => cmd.name.toLowerCase() === commandName.toLowerCase()
+  ) ?? null
+}
+
+async function formatCommandTemplate(cmd: CommandInfo, args: string): Promise<string> {
+  const sections: string[] = []
+
+  sections.push(`# /${cmd.name} Command\n`)
+
+  if (cmd.metadata.description) {
+    sections.push(`**Description**: ${cmd.metadata.description}\n`)
+  }
+
+  if (args) {
+    sections.push(`**User Arguments**: ${args}\n`)
+  }
+
+  if (cmd.metadata.model) {
+    sections.push(`**Model**: ${cmd.metadata.model}\n`)
+  }
+
+  if (cmd.metadata.agent) {
+    sections.push(`**Agent**: ${cmd.metadata.agent}\n`)
+  }
+
+  sections.push(`**Scope**: ${cmd.scope}\n`)
+  sections.push("---\n")
+  sections.push("## Command Instructions\n")
+
+  const commandDir = cmd.path ? dirname(cmd.path) : process.cwd()
+  const withFileRefs = await resolveFileReferencesInText(cmd.content || "", commandDir)
+  const resolvedContent = await resolveCommandsInText(withFileRefs)
+  sections.push(resolvedContent.trim())
+
+  if (args) {
+    sections.push("\n\n---\n")
+    sections.push("## User Request\n")
+    sections.push(args)
+  }
+
+  return sections.join("\n")
+}
+
+export interface ExecuteResult {
+  success: boolean
+  replacementText?: string
+  error?: string
+}
+
+export async function executeSlashCommand(parsed: ParsedSlashCommand): Promise<ExecuteResult> {
+  const command = findCommand(parsed.command)
+
+  if (!command) {
+    return {
+      success: false,
+      error: `Command "/${parsed.command}" not found. Use the slashcommand tool to list available commands.`,
+    }
+  }
+
+  try {
+    const template = await formatCommandTemplate(command, parsed.args)
+    return {
+      success: true,
+      replacementText: template,
+    }
+  } catch (err) {
+    return {
+      success: false,
+      error: `Failed to load command "/${parsed.command}": ${err instanceof Error ? err.message : String(err)}`,
+    }
+  }
+}