Type Expand

Type Expand

Codex Compatibility

When running this skill in Codex, translate Claude Code-only primitives before acting: AskUserQuestion -> chat/request_user_input, TodoWrite -> update_plan, Task/TaskCreate/TeamCreate/SendMessage -> spawn_agent/send_input/wait_agent when available and allowed, and EnterPlanMode/ExitPlanMode -> a concise chat plan plus explicit approval. Resolve Read/Write/Edit/Bash/WebSearch/WebFetch to Codex file/shell/web tools, and map ~/.claude/... paths to ~/.agents/... or ~/.codex/... unless the task explicitly targets Claude Code.

Cursor Compatibility

When running this skill in Cursor Agent, translate Claude Code-only primitives before acting: AskUserQuestion -> AskQuestion; TodoWrite -> Cursor TodoWrite or an equivalent checklist; Task/TaskCreate/TeamCreate/SendMessage/multi-agent flows -> Cursor Task (subagents), parallel Tasks, or run_in_background when allowed (TeamCreate/SendMessage may have no exact match); EnterPlanMode/ExitPlanMode -> Plan mode (SwitchMode / CreatePlan) plus explicit user approval. Resolve Read/Write/Edit/StrReplace/Bash/web/search/MCP via Cursor Composer or Agent equivalents. MCP names written as mcp__server__tool typically map to call_mcp_tool with configured server identifiers. Map ~/.claude/... to ~/.cursor/skills/, .cursor/skills/, and .cursor/rules/ unless the task explicitly targets Claude Code.

Purpose

Use this skill to inspect the real shape of complex TypeScript types when IDE hover is not enough.

Inputs

Use one of these:

• Selected code that includes a target type alias.
• filePath + typeName.
• A direct alias snippet (export type X = ...).

Workflow

1. Identify target alias name and source file.
2. Run the expander script:

pnpm exec tsx ~/.agents/skills/type-expand/scripts/expand-type.ts --file <filePath> --type <typeName>

（Claude Code: ~/.claude/skills/...、Cursor: ~/.cursor/skills/... または .cursor/skills/... に symlink される）

3. If project root cannot be inferred, pass tsconfig path:

pnpm exec tsx ~/.agents/skills/type-expand/scripts/expand-type.ts --file <filePath> --type <typeName> --project <tsconfigPath>

4. Return output in this format:

export type <TypeName> =
| <expanded object type>
| <expanded object type>

5. If part of the type cannot be fully resolved, keep best-effort expansion and annotate unresolved fragments inline.

Expansion Policy

• Prefer concrete object property expansion over alias names.
• Recursively expand unions/intersections.
• Expand instantiated generics where type arguments are known.
• Resolve conditional types (extends) and infer-derived parts when checker provides concrete results.
• Flatten common utility-type transformations when symbol/property info is available (Pick, Omit, Partial, Required, Readonly, Record, Exclude, Extract, NonNullable).
• Enforce depth and cycle guards to prevent runaway expansion.

Output Style

• Keep property names stable and readable.
• Preserve optional (?) and readonly modifiers when detectable.
• Use unknown for recursion/depth guard fallbacks.

Additional Resource

• See reference.md for command examples and troubleshooting.