# Research TS Decisions > Research why the TypeScript team made a specific typing decision. Use when evaluating whether ts-reset should override a built-in type, or when triaging issues that propose type changes. Searches the microsoft/TypeScript repo for relevant issues, PRs, and team comments. Use when this capability is needed. - Skill: `tomevault-io/research-ts-decisions` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/research-ts-decisions` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/research-ts-decisions/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Research & Search - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/research-ts-decisions --- # Research TypeScript Team Decisions When evaluating whether ts-reset should override a TypeScript built-in type, research what the TypeScript team has said about it. Understanding their reasoning lets us make informed decisions — either agreeing with their trade-off or deliberately choosing a different one. ## Who to look for **Ryan Cavanaugh** (`@RyanCavanaugh`) is the TypeScript project lead and usually the one making final verdicts on typing decisions. His comments carry the most weight. Also look for comments from: - **Daniel Rosenwasser** (`@DanielRosenwasser`) — TS program manager - **Anders Hejlsberg** (`@AHejlsberg`) — original designer - **Nathan Shively-Sanders** (`@sandersn`) ## How to search ### Step 1: Search GitHub issues directly Use `gh` to search the microsoft/TypeScript repo. Try multiple queries — the issue might be about the specific method, the return type, or a broader pattern: ```bash # Search issues by title/body gh search issues --repo microsoft/TypeScript "Object.create return type" --limit 20 # Search with broader terms if the first query is too narrow gh search issues --repo microsoft/TypeScript "Object.create" --limit 20 ``` ### Step 2: Find team member comments Once you have candidate issues, fetch comments and filter for TypeScript team members: ```bash # Get Ryan's comments on a specific issue gh api repos/microsoft/TypeScript/issues/{number}/comments \ --jq '.[] | select(.user.login == "RyanCavanaugh") | {html_url, body}' # Check for team comments more broadly gh api repos/microsoft/TypeScript/issues/{number}/comments \ --jq '.[] | select(.user.login == "RyanCavanaugh" or .user.login == "DanielRosenwasser" or .user.login == "sandersn" or .user.login == "ahejlsberg") | {user: .user.login, html_url, body}' ``` ### Step 3: Check for reverted PRs Many typing decisions were tried, broke things, and got reverted. This history is critical: ```bash # Search for PRs related to the topic gh search prs --repo microsoft/TypeScript "Object.create" --limit 20 # Check if a PR was later reverted gh api repos/microsoft/TypeScript/pulls/{number} --jq '{title, state, merged_at, body}' ``` ### Step 4: Search for related issues TypeScript team members often state general principles on tangentially related issues. If the specific method doesn't have much discussion, search for related patterns: ```bash # Example: if researching Object.create, also check Object.getPrototypeOf, # or broader topics like "prototype typing" or "returns any" gh search issues --repo microsoft/TypeScript "Object.getPrototypeOf any" --limit 10 ``` ### Step 5: Web search as fallback If GitHub search doesn't surface enough, use web search: ``` site:github.com/microsoft/TypeScript "Object.create" RyanCavanaugh ``` ## What to report Structure your findings as: 1. **Timeline** — chronological list of relevant issues and PRs, with links 2. **Key quotes** — direct quotes from team members, with permalink URLs to the specific comments (not just the issue) 3. **The reasoning** — summarize why the current typing exists 4. **Was it tried before?** — note any attempts to change it that were reverted or rejected, and why 5. **Relevance to ts-reset** — does this fall in ts-reset's sweet spot, or is the current typing a deliberate trade-off? Always include direct permalink URLs to specific comments, not just issue URLs. Use the `html_url` field from the GitHub API. ## Common patterns in TS team reasoning These recurring arguments come up frequently. Knowing them helps you search more effectively and contextualize what you find: - **"`any` can never be wrong, just less right"** — Ryan's principle that `any` is a safe default that never produces false errors - **Breaking changes** — the TS team is very cautious about changing return types that would break existing code - **"Soundness is not a goal"** — TypeScript explicitly prioritizes practical usability over type-theoretic correctness - **Prototype vs own properties** — methods dealing with prototypes are hard to type because TS's type system doesn't distinguish prototype properties from own properties - **`PropertyDescriptorMap` is untyped** — any API that takes property descriptors can't carry type information through them --- > Source: [mattpocock/ts-reset](https://github.com/mattpocock/ts-reset) — distributed by [TomeVault](https://tomevault.io).