Verify Directory Structure — Parallel Audit

This skill provides a systematic approach to diagnosing file access issues and auditing source trees efficiently. It extends basic directory verification with parallel batch file reading (dramatically reducing iteration count when many files must be inspected) and a dedicated TypeScript import validation phase that catches a common class of structural bugs.

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Steps

Phase 1 — Directory Verification

1. Identify Target Paths: Collect every file or directory path involved in the operation. Prefer absolute paths to eliminate ambiguity.

2. Enumerate with list_dir: Call list_dir on each relevant directory. Record all file names, sizes, and modification dates. This is your ground truth before touching any file.

3. Verify Existence & Permissions: Confirm the directory exists and that the current user has read (and, if needed, write/execute) permissions. If a directory is missing, create it before proceeding. If permissions are insufficient, adjust them before retrying.

4. Build a File Manifest: From the list_dir output, compile the complete list of files to be audited. Group them logically (e.g., by subdirectory or file type) so they can be read in parallel batches.

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Phase 2 — Parallel Batch File Reading

Why this matters: Reading files sequentially costs one iteration per file. Reading them in parallel batches collapses N files into ⌈N/batch_size⌉ iterations — a significant speedup when auditing dozens of files.

5. Determine Batch Size: Default to reading 5–10 files per batch. Reduce the batch size if individual files are very large; increase it for small config/index files.

6. Issue Parallel read_file Calls: Within each batch, invoke read_file for all files simultaneously (a single iteration). Do not wait for one file before requesting the next within the same batch.

   Batch 1 (parallel): read_file(src/components/A.tsx)
                        read_file(src/components/B.tsx)
                        read_file(src/components/C.tsx)
                        read_file(src/components/D.tsx)
                        read_file(src/components/E.tsx)
   
   Batch 2 (parallel): read_file(src/components/F.tsx)
                        ...
   

7. Collect & Triage Results: After each batch completes, scan results for errors (file-not-found, permission denied) and flag them immediately. Do not abort the remaining batches; continue and aggregate all findings.

8. Re-verify Missing Files: For any file reported as missing, re-run list_dir on its parent directory to confirm whether the file truly does not exist or whether the path was wrong. Correct the path and retry the single file if necessary.

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Phase 3 — TypeScript Import Validation

This phase targets a common class of structural bugs found when auditing TypeScript source trees.

9. Identify Import Statements: For every .ts / .tsx file read in Phase 2, extract all import lines.

10. Classify Import Kind — Value vs. Type:

    Pattern	Correct usage
    import Foo from '...'	Runtime value (class, function, object)
    import { Foo } from '...'	Runtime value export
    import type Foo from '...'	Type-only import (erased at compile time)
    import type { Foo } from '...'	Type-only named import
    import { type Foo } from '...'	Inline type modifier (TS 4.5+)

11. Flag Value Imports Used Only as Types: If an identifier imported without type is used only in type positions (: Foo, as Foo, implements Foo, generic parameters), it should be converted to import type. This prevents accidental runtime dependencies and satisfies verbatimModuleSyntax / isolatedModules compiler flags.

    // ❌ Before — value import used only as a type
    import { UserProfile } from './types';
    const handler = (u: UserProfile) => { ... };
    
    // ✅ After — type-only import
    import type { UserProfile } from './types';
    const handler = (u: UserProfile) => { ... };
    

12. Flag Duplicate Imports: Detect cases where the same module is imported more than once in a file (often from copy-paste). Merge them into a single import statement.

    // ❌ Duplicate
    import { A } from './utils';
    import { B } from './utils';
    
    // ✅ Merged
    import { A, B } from './utils';
    

13. Verify Barrel / Index Exports: When a directory contains an index.ts (barrel file), confirm that every component or module expected to be publicly accessible is re-exported. Cross-reference against the file manifest from Phase 1.

14. Apply Fixes & Re-audit: Apply all import corrections as a single write pass per file. After writing, re-read the affected files (parallel batch) to confirm the fixes took effect.

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Phase 4 — Final Validation & Report

15. Retry the Original Operation: With the directory structure confirmed and import issues resolved, retry the operation that originally failed.

16. Log an Audit Report: Produce a concise summary covering:

    • Total files enumerated and read
    • Number of batches used (highlight the iteration savings vs. sequential)
    • Import issues found and fixed (value→type conversions, duplicate merges, missing barrel exports)
    • Any remaining unresolved issues with recommended next steps

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Quick Reference: Batch Reading Pattern

# Sequential (slow) — N iterations for N files
read_file(file1) → wait → read_file(file2) → wait → ...

# Parallel batch (fast) — ⌈N/B⌉ iterations for N files, batch size B
[read_file(file1), read_file(file2), ..., read_file(fileB)]  ← 1 iteration
[read_file(fileB+1), ...]                                     ← 1 iteration

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Best Practices

• Always enumerate before reading: list_dir first, then batch-read. Never guess file names.
• Use absolute paths throughout to avoid working-directory ambiguity.
• Batch by locality: Group files from the same directory in the same batch to keep context coherent.
• Type imports are zero-cost at runtime: Prefer import type for any symbol used exclusively as a TypeScript type. This is especially important in projects with isolatedModules: true.
• Barrel files are contracts: Treat index.ts exports as the public API of a module. Missing exports are bugs even if the underlying file is correct.
• Log intermediate findings: If issues persist after Phase 3, dump the full audit log for offline debugging.

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Common Fix Categories (Checklist)

• Directory missing → create with mkdir -p
• Permissions insufficient → chmod/chown or escalate
• Path typo → re-enumerate with list_dir, correct path
• Value import used as type → add import type
• Duplicate imports → merge into single statement
• Missing barrel export → add re-export to index.ts
• Circular import → restructure module boundaries