Vendored parser (Apache-2.0)

FlowDelta does not parse Flow XML itself. The parser is vendored from Google’s upstream Flow Lens project (google-flow-lens) and lives, unmodified, at:

src/parser/flow_parser.ts
src/parser/flow_types.ts

Naming distinction

FlowDelta is this project and its semantic diff/render pipeline. Google Flow Lens (google-flow-lens) refers only to the upstream project from which the parser is vendored. Do not use Flow Lens as a name for FlowDelta-authored code or behavior.

Provenance

Upstream: Google Flow Lens (google-flow-lens), Apache License 2.0.
Vendored commit: see NOTICE at the repo root (records the exact upstream SHA).
The vendored files retain their original Apache-2.0 headers; NOTICE records the attribution.

Do not edit

Treat src/parser/ as read-only. Its behavior is pinned by test/parser.test.ts (the upstream suite, ported to node:test), which proves the parser runs identically under Node. Edits would diverge from upstream, break that guarantee, and complicate any future re-sync. All FlowDelta-specific behavior belongs in the layers built on top of the parser (model/, diff/, render/).

Why vendor only the parser

A spike confirmed the parser is runtime-agnostic; it imports only xml2js plus its own type module, with zero Deno APIs, so it copies into a Node/TypeScript project verbatim. The upstream diff/render layers were not adopted; FlowDelta provides its own normalized model, canonicalization, edge-aware diff, per-property deltas, and interactive HTML — the gaps upstream doesn’t cover.

License interaction

FlowDelta is a mixed-license project: MIT and Apache-2.0. FlowDelta-authored code is MIT (LICENSE); the Google Flow Lens parser is Apache-2.0. The project is not relicensing the parser as MIT.

To stay compliant with Apache-2.0 when redistributing (including npm publish), all of the following must travel together:

src/parser/* original Apache-2.0 headers (do not strip): §4(c).
LICENSE-APACHE, the full Apache-2.0 text: §4(a).
NOTICE, attribution + upstream commit: §4(d).

The parser is vendored verbatim, so there are no “modified file” notices to add under §4(b); if that ever changes, mark the modified files prominently.