Upgrade Dependencies

Drive a dependency upgrade from "bump X to latest" all the way to green — without hacking around the errors it causes.

Core principle: fix upward, never patch sideways. When a bump breaks something, the fix is to upgrade the thing that's incompatible to a version that supports the target — not to suppress the error, downgrade the target, or add // @ts-ignore. If nothing upstream supports the target yet, that's a blocker you report, not a workaround you invent.

JS/TS ecosystems only (npm / pnpm / yarn / bun, including workspace monorepos and nx/turbo).

The workflow

Work the phases in order. Scan the full impact (phase 2) before touching anything, and collect all breakage (phase 4) before fixing — otherwise you'll fix the same file three times and discover missed references halfway through.

1. Resolve the target version

• Absolute latest stable by default: npm view <pkg> version (dist-tag latest). Ignore existing semver ranges — the user asked to upgrade.
• Use a prerelease (next/rc/canary) only if the user asked for it, or if it's the only version that unblocks a phase-5 blocker (and say so).
• Detect the package manager from the lockfile: pnpm-lock.yaml→pnpm, bun.lockb→bun, yarn.lock→yarn, package-lock.json→npm. Never substitute a different runner.
• Detect monorepo layout: root workspaces, pnpm-workspace.yaml, nx.json, turbo.json.