arkts-skill

name	arkts-skill
description	ArkTS language specification guidance for syntax, types, semantics, and diagnostics based on ArkTS Specification 1.2.0. Use when handling ArkTS grammar questions, compiler/type errors, feature compliance checks, TypeScript-to-ArkTS adaptation, or HarmonyOS ArkTS code modernization.

ArkTS Skill

Use this skill to answer ArkTS language and type-system questions with spec-backed guidance.

Workflow

1. Read the user problem and classify it as one of: syntax, type system, declarations, expressions/statements, classes/interfaces, or migration/compatibility.
2. If the question is TypeScript-to-ArkTS migration related (especially "why not supported", including destructuring-assignment concerns), read references/huawei-migration-priority.md first.
3. For migration questions, use local files in references/huawei-migration/*.md first (local-first).
4. If local migration files are stale or insufficient, refresh them via bash scripts/fetch_huawei_migration_refs.sh.
5. Search chapter files, then open only the matched files.
6. Cite the exact section/topic names in your answer.
7. Prefer minimal, directly compilable ArkTS examples.
8. Keep recommendations simple and deterministic. If multiple options exist, present the simplest compliant one first.

Fast Search Patterns

Use targeted search on the chapter directory:

• bash scripts/search_chapters.sh "union|narrow|keyof"
• rg -n "type|union|interface|class|function|async|decorator|generic" references/chapters
• rg -n "assignment|narrow|overload|extends|implements|readonly|tuple|array|literal" references/chapters
• rg -n "error|diagnostic|restriction|forbidden|not allowed|shall|must" references/chapters

Maintenance

• Rebuild chapter split from full OCR markdown:
  • python3 scripts/rebuild_chapters.py
• Refresh migration local references:
  • bash scripts/fetch_huawei_migration_refs.sh
• Keep references/CHAPTER_INDEX.md in sync with chapter files after rebuild.

Output Rules

• Prefer short explanations with one concrete fix.
• For compiler/type errors, include:
  • Root cause in one sentence.
  • Smallest valid code change.
  • Why this matches spec behavior.
• For migration questions, produce a before/after snippet and list breaking points.

Compile Error Fix Playbook (Field-tested)

Use this checklist first when ArkTS build fails with strict diagnostics:

1. Reproduce with CLI and capture exact diagnostics:
   • hvigorw assembleHap
2. Map each error code to one direct rewrite, then recompile immediately.

Frequent Errors and Minimal Fixes

• arkts-no-untyped-obj-literals:
  • Root cause: inline object literals in places where ArkTS requires explicit class/interface instances.
  • Fix: replace { ... } values with class instances (new Xxx(...)) or strongly typed containers.
• arkts-no-obj-literals-as-types:
  • Root cause: using object literal shape directly in type positions (for example inline { v: string, w: number } arrays).
  • Fix: extract a named class/interface (for example WeightedItem) and use that type.
• arkts-no-props-by-index:
  • Root cause: dynamic property indexing on fields like obj[key].
  • Fix: replace with Map<K,V> (get/set) or explicit switch/branch lookup.

Practical Rewrite Patterns

• Record<string, T> dictionaries with dynamic keys:
  • Prefer Map<string, T> for mutable runtime lookup.
• i18n maps accessed by I18N[lang][key]:
  • Replace with deterministic switch function (t(key)), especially when key is runtime string.
• Bigram/follower tables as plain object literals:
  • Replace with explicit lookup function followersOf(ch) using switch.
• Weak-key and weighted pools:
  • Replace anonymous object items with named classes (WeakKey, WeightedItem) to satisfy strict typing.

Validation Loop

1. Change the smallest failing region.
2. Re-run hvigorw assembleHap.
3. Continue until only warnings remain.
4. Report separately:
   • Compile blockers fixed.
   • Remaining warnings (deprecated APIs, throw-handling hints).

Reference

• Full OCR markdown: arktsspecification_ocr_full.md
• Chapter index: references/CHAPTER_INDEX.md
• OCR chapter files: references/chapters/*.md
• Migration-first references: references/huawei-migration-priority.md
• Migration local files: references/huawei-migration/*.md