Ecosystem and production
The Provenance Was Valid. The Commit Was Not.
An npm provenance attestation binds a tarball to a repository, a workflow and a commit. Reading the payload shows what it never claims.
JavaScript, TypeScript, and the runtimes underneath
What JavaScript and TypeScript actually do, one layer down
JS Ledger examines JavaScript, TypeScript, and the runtimes, frameworks, and tooling behind modern web applications.
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Frameworks
Your Reactive Graph Computed 4,11. That State Never Existed.
A single-pass push through a diamond recomputes the leaf twice, and the first result mixes a fresh value with a stale one. Two passes are what remove it.
Language internals
Your Conditional Type Answered Twice. Both Answers Are Right.
A naked type parameter splits its union before the conditional runs, so IsArray<string[] | number> comes back as 'no' | 'yes'. Read out of TypeScript 7.0.2.
Tooling and build
Vite 8 Ships One Bundler, Not One Pipeline
Vite 7 depends on esbuild and Rollup; Vite 8 on neither. Serving one module from both majors shows what the swap to Rolldown changed and what it left alone.
Runtime and performance
Object Shapes Are a Tree, and the Tree Is Shared
A hidden class is a node in a transition tree V8 keeps for the whole isolate — which is why an unrelated function can decide how your object is stored.
Language internals
What await Compiles To, and What It Costs
One async function compiled three ways — TypeScript's ES5 emit, V8's bytecode and the spec's Await steps — and the microtask turns each one predicts.
Ecosystem and production
Reading a Lockfile: Supply Chain in Practice
What package-lock.json actually records, what its integrity hashes do and do not prove, and where the real install-time risk sits.
Sections
The pillars
- Language internals3 articles
- Runtime and performance3 articles
- Ecosystem and production2 articles
- Frameworks2 articles
- Tooling and build2 articles
Read in order
Series
- Series 01
Async machinery
2 parts - Series 02
Reactivity
2 parts - Series 03
The build pipeline
2 parts - Series 04
The software supply chain
2 parts - Series 05
The TypeScript type system
2 parts - Series 06
The V8 object model
2 parts