TypeScript Type-Check with shell_agent Fallback

When verifying TypeScript compilation as part of a build or validation workflow,

run_shell

run_shell

shell_agent

When to Use

• After creating or modifying TypeScript source files and you need to confirm there are no type errors.
• As part of a CI-like verification step inside an autonomous workflow.
• Any time

  run_shell

  returns an unexpected or unclear error for a

  tsc

  invocation.

Step-by-Step Pattern

Step 1 — Attempt with

run_shell

(fast path)

Try the direct command first. This is fast and gives immediate output when the environment is well-configured.

run_shell: npx tsc --noEmit

Evaluate the result:

• ✅ Exit code 0, no errors → Type-check passed. Done.
• ❌ Exit code non-zero with TypeScript diagnostics → Real type errors exist; surface them and fix.
• ⚠️ Unknown error, timeout, or no useful output → Proceed to Step 2.

Step 2 — Fall back to

shell_agent

(reliable path)

When

run_shell

shell_agent

shell_agent

• Locate the correct

  npx

  /

  tsc

  binary
• Retry on transient failures
• Navigate PATH or permission issues
• Return a structured summary of any type errors

Task string to pass to

shell_agent

Run `npx tsc --noEmit` in the project root and report all TypeScript type errors found. If there are no errors, confirm the compilation succeeded. If tsc is not available, attempt to install TypeScript locally with `npm install --save-dev typescript` first.

Evaluate the result:

• ✅ "No errors found" / exit 0 → Type-check passed.
• ❌ Type errors listed → Collect and fix the reported diagnostics, then re-run.
• ⚠️

  tsconfig.json

  missing → Ensure the file exists in the project root before re-running.

Decision Flowchart

run_shell("npx tsc --noEmit")
        │
        ├─ success (exit 0) ──────────────────► ✅ PASS
        │
        ├─ type errors reported ──────────────► ❌ Fix errors, retry
        │
        └─ unknown/env error ─────────────────► shell_agent(natural-language task)
                                                        │
                                                        ├─ success ───► ✅ PASS
                                                        └─ errors  ───► ❌ Fix & retry

Example Implementation

# Pseudo-code for an autonomous agent loop

result = run_shell("npx tsc --noEmit", timeout=60)

if result.exit_code == 0:
    print("TypeScript check passed.")

elif result.exit_code != 0 and result.stderr contains "TS\d+":
    # Real TypeScript diagnostics — surface and fix them
    raise TypeScriptError(result.stderr)

else:
    # Ambiguous failure — delegate to shell_agent
    shell_agent(
        task="Run `npx tsc --noEmit` in the project root and report all TypeScript "
             "type errors found. If there are no errors, confirm compilation succeeded. "
             "If tsc is not available, install it first with `npm install --save-dev typescript`."
    )

Tips

• Always have a

  tsconfig.json

  :

  tsc --noEmit

  requires a valid config. If none exists, generate one first with

  npx tsc --init

  .
• Set a reasonable timeout: TypeScript compilation on large projects can take 30–120 seconds. Give

  run_shell

  at least

  timeout=90

  .
• Scope to changed files when possible: Use

  --project tsconfig.json

  or a path glob to limit what tsc checks if only a subset of files changed.
• Prefer

  shell_agent

  for first-time setups: If the project environment is freshly created and dependencies may not be fully installed, start with

  shell_agent

  directly to avoid a predictable

  run_shell

  failure.

Generalizing Beyond TypeScript

This same fallback pattern applies to any build/lint/type-check command that may be sensitive to shell environment:

run_shell

shell_agent

npx tsc --noEmit

npx eslint src/

python -m mypy src/

go build ./...

The core principle:

run_shell

shell_agent