Status: seven cross-built variants and four native host types verified. Linux x64 source desktop/installer/updater smoke passes; other source profiles remain open.
Build Electron apps as Bazel targets. Cache compiler, generator, app and packaging actions independently. Build inputs come from declared files and pinned repositories.
flowchart TD
Release[Electron release + DEPS + patches] --> Overlay[formatjs/electron]
Chromium[formatjs/chromium build machinery] --> Overlay
Node[hermeticbuild/nodejs build machinery] --> Overlay
Overlay --> Runtime[Target Electron + runtime files]
HostNode[Execution-platform Node toolchain] --> JS[App JS build rules]
JS --> AppFiles[Main + preload + renderer + assets]
Runtime --> Adapter[electron_runtime]
Adapter --> App[electron_app]
AppFiles --> App
Native[Target Node-API addon + helper] --> App
App --> Directory[Target app directory / macOS app ZIP]
Directory --> Future[Future archives / installers]
formatjs/electron owns source pins, patches, generators, native libraries and
runtime linking. rules_electron owns app layout, ASAR, runtime selection,
installers and distribution metadata. Existing JS rules own TypeScript, bundling
and npm dependency resolution. No electron-builder subprocess hidden behind one
Bazel action.
Electron selects its Node, Chromium and V8 dependency closure. Reuse build machinery from hermeticbuild/nodejs and formatjs/chromium without substituting their current dependency versions. Host Node tools use execution configuration; Electron and native addons use target configuration. Native addon integration must include Electron's headers, ABI and build flags, beyond Node's version alone.
electron_runtime(binary, files) adapts declared source-build outputs into
ElectronRuntimeInfo. Files map to paths relative to Electron's distribution
root. Explicit runtime dependency keeps source version visible at the app target;
runtime toolchain selection can follow once a real source runtime exists.
electron_app(runtime, package_json, srcs) writes one directory artifact. App
files map to resources/app, retaining renderer/preload paths. Optional ASAR
packs those files with per-file SHA256 block hashes; explicit unpacked files sit
alongside the archive. Extra resources remain outside ASAR. Assembly copies
inputs, rejects traversal and overlapping destinations, normalizes modes and
timestamps. No host filesystem discovery or target execution. Pinned Python
executes the assembly action. App/resource mappings accept declared tree artifacts;
their regular files expand under the mapped prefix. Directory symlinks fail;
Bazel input-projection file symlinks are dereferenced into regular output files.
Runtime adapters still require explicit regular-file mappings.
Linux v1 fuse settings patch only the output binary, leaving source inputs alone. Unknown, removed, truncated or ambiguous fuse wires fail. Only supported settings are exposed; embedded ASAR integrity/signature metadata is outside this feature.
Linux/Windows directory layouts and macOS framework/helper bundle structure have dedicated assembly paths. macOS re-signs ad hoc using an execution-platform tool and returns a ZIP preserving framework symlinks. Release signing, Windows PE icons and remaining platform installers still need dedicated rules. Setuid sandbox packaging also needs a format that carries installation permissions. Native runtime smoke must use a working sandbox.
Source-built Electron remains unlinked. The Electron overlay now builds and runs the complete patched V8 engine, inspector and generated snapshots. Its new native targets contain 1,453 C++/assembly units, reusing existing base libraries and native generators. Matching source-built dependencies include ICU, PartitionAlloc, Temporal Rust, Protobuf, Perfetto and compression/SIMD libraries. Electron builtin JS, webpack bundles, patched libuv/BoringSSL and eleven Node support libraries also build.
4516ed7 components, BCR consumer and cross checks passed. The runtime probe uses actual generated snapshots and declared ICU data; it executes JS, Wasm, Intl, Rust-backed Temporal and inspector evaluation, then checks context state after collection. Captured pointer compression, sandbox and tracing flags stay enabled. Generators verify path/mtime reproducibility; snapshot code generation disables host CPU probing. These full source profiles remain Linux AMD64.
Patched libnode now builds its 171 C/C++ units with original inspector and compression dependencies (239 new units total). 40b2baf consumer passed actual Node environment startup/shutdown, ABI 140, Node-API 10 shared-addon loading, original-fs, async FS, crypto, Brotli/Zstd, SQLite and inspector evaluation. A declared compatibility patch keeps the Node platform registered during V8 isolate disposal, matching Electron's existing main-instance ordering. Parent source trees stay unchanged.
Matching Gin, Base i18n and CED add 56 original C++ units with shared V8/Base/ICU dependencies. 5bca689 consumer passed native callbacks, invalid argument rejection, sandboxed ArrayBuffers, collection/shutdown and Unicode conversion/segmentation. Both ICU and generated V8 startup data are declared files. This full profile remains Linux AMD64.
Chromium-configured IPCz adds its complete 36-unit core, shared Base/Abseil and original source-set linkage. c961819 consumer passed broker/client binary messaging, receive-capacity errors, portal transfer, peer closure and cleanup with the original synchronous reference driver. No standalone IPCz implementation replaces Chromium's configuration.
Mojo core/platform/embedder and networking now build their captured closure: 1,124 new C/C++ units plus 34 matching BoringSSL PKI units, original generators and native NSS/NSPR. Shared Base, ICU, IPCz, Protobuf and compression targets stay reused. 122f977 consumer passed binary messages, data pipes, shared mappings, SQL, URL/IDNA, suffix/HSTS lookups and original NSS integrity verification, including corruption rejection. HSTS tests retain its 70-day expiry policy. This full profile remains Linux AMD64.
Typed Mojo bindings now add 214 C++ units and 29 original Python actions for Mojo base types and service-manager interfaces. 8261fc4 consumer passed real parent/child invitation transport, generated InterfaceProvider dispatch with embedded-NUL strings, transferred shared-memory coherence, reply-pipe transfer and malformed-message rejection. Original source headers stay shared with networking; no substitute transport participates. This full profile remains Linux AMD64.
Native rendering dependencies now include the full captured FreeType, HarfBuzz, libpng and libxml roots: 142 C/C++ units with original Chromium settings. 854f6a7 consumer passed ligature shaping, glyph rasterization, RGBA PNG roundtrip and XML/XPath checks. Source archives use exact DEPS commits plus checksums; ICU and zlib stay shared. This profile remains Linux AMD64.
Fontconfig now adds its full captured 29 C units plus original Rust fontations: nine new library/proc-macro targets and one libc build script. The shared Rust profile contains 95 targets from 71 packages; previous 85 Rust records remain unchanged. Native pinned bindgen preserves the original C headers and Rust wrapper. 6652729 consumer passed explicit-config fontations scanning, metadata/charset checks, native matching, invalid-font rejection and inventory cleanup using only declared font bytes. Native BCR libuuid supplies UUID support.
Native JPEG, WebP and Wuffs GIF now add 213 product C units. JPEG retains 27 original SIMD assembly runs, using all 81 captured C units of its matching NASM 2.17rc0 on the execution platform. Assembly output bytes match across changed paths/mtimes. a4c1c6a consumer passed real JPEG SIMD/color, lossless WebP alpha, GIF pixel/frame completion and invalid-stream checks. This full profile remains Linux AMD64.
The complete matching Skia root now adds 1,158 C++ units in 27 native targets, 15 original generator actions and original Rust PNG/fontations bridges. The shared Rust profile contains 107 targets from 80 packages; previous 95 Rust records remain unchanged. Exact DEPS archive pins retain Skia/Dawn/Vulkan configuration; existing fonts/codecs/Base stay shared. PartitionAlloc exports 62 original pointer headers, and Wuffs exports its original public include path. 3d7a5d1 consumer passed exact SkSL raster pixels, invalid shaders, Rust PNG RGBA/alpha, invalid PNG/font input and original fontations glyph paths through CXX. This complete profile remains Linux AMD64; hardware GPU contexts remain untested.
The matching gfx closure adds 351 C/C++/assembly units, 34 original generators and four literal GN metadata targets. Native libdrm/libsync, Electron-patched Crashpad, geometry/range wire types, image codecs, memory buffers and binary data packs retain original sources. Skia/Mojo/fonts/Base providers remain shared. 8f46f43 consumer passed transform/wire, PNG alpha, buffer layout/overflow, DRM metadata and deterministic binary data-pack checks. This full profile remains Linux AMD64.
Native display adds 118 units in 22 library/group targets, 21 original generators and three literal GN metadata targets. Full display/gfx wire bindings reuse existing gfx/Skia/Mojo/Base providers. 81686a0 consumer passed logical/native scaling, relocated work areas, monitor change notifications, wire roundtrips and malformed screen-list rejection. Physical display/GPU execution remains untested; full source profiles remain Linux AMD64.
The complete native events closure adds 417 units, 76 original generators, seven GN metadata targets and original X11 protocol copies. It retains existing native tracing/Protobuf providers and execution-platform plugins. Native XCB reuses pinned BCR sources with declared Python generation/copy actions; native XKB compiles its parser from source. 076dc2e consumer passed modifier/clone and coordinate transforms, explicit keyboard-state changes, original X11 wire decoding, native display-string parsing and binary Snappy roundtrip/truncation checks. Test data does not discover a host keyboard layout or X server. Full profiles remain Linux AMD64; physical-device execution and complete Electron remain unfinished.
Native UI adds 96 units in 76 library/group targets, 339 original Python actions, 24 GN metadata targets and 15 copy steps. The source closure retains original TypeScript, ESLint, minification, GRIT and locale producers. Pinned execution Node and prepatched npm sources are separate from Electron's embedded Node. 2b46400 consumer passed relocated locale reloads, packed WebUI byte checks, native color mixing and generated JavaScript execution.
Remaining source work includes electron_lib, Chromium Blink/content
libraries, the other full source profiles and runtime packaging. The
Chromium build has a validated Linux browser
and uses the same V8 base revision, bb294624702efbb17691b642333f06bf5108e600.
Reuse its native machinery with Electron's patches and captured configuration.
Once Electron links, expose executable plus complete runtime files with stable relative paths. Consume them here; run a relocated app creating a BrowserWindow, loading local renderer assets and exercising a preload IPC roundtrip. Existing fixtures remain the fast packaging regression suite.
Source builds should eventually use the source Node toolchain for execution tools. Required bootstrap runtimes must stay explicit. The assembler itself needs no Node toolchain.
Follow rules_formatjs: BuildBuddy workflow triggers for main, pull requests and merge queue; Linux remote execution, shared cache/BES, five-platform cross-build matrix. Hermetic LLVM cross-links a native fixture for Linux x86_64/arm64, macOS x86_64/arm64 and Windows x86_64 (MinGW fixture). Electron's actual Windows runtime needs MSVC; that toolchain requires an explicitly approved Visual Studio runtime license setting. Both MSVC CPU variants have native smoke coverage. Assembly uses Linux execution tools. Linux tests execute assembled fixture after relocation. No cross-target test execution implied. Add real Electron targets to this matrix as each upstream source profile becomes available; keep unsupported profiles explicit.
The independent examples/desktop workspace provides a generic app built from
scratch, with a real Node-API addon and helper compiled by LLVM. Explicitly
labeled official Electron bootstraps make it runnable before the source runtime
exists. BB Linux workers compile and package every variant. GH downloads the
verified host-specific archives, then native Linux x64, macOS ARM64 and Windows
x64/ARM64 hosts execute sandboxed relocation smoke. Both Windows compiler
variants run on their matching CPU host. Linux ARM64 is cross-built only.
No credentials checked in. Hosted CI requires repository hookup and BuildBuddy access. Larger source-runtime jobs need separate memory/disk budgets; fixture budgets do not estimate Chromium compilation costs.
Upstream native rules now build Ozone/GL, ANGLE, SwiftShader, Vulkan and Wayland components. Source GLib/GObject/GModule/GIO and zlib have shared owners with their original SONAMEs. Platform/SDK header contexts stay separate from linking; native Rust FFI libraries remain explicit dependencies.
flowchart LR
GN[Captured GN declarations] --> Native[Native C/C++/Rust rules]
Native --> Graphics[ANGLE / SwiftShader / Vulkan]
Shared[Source GLib / zlib shared owners] --> Graphics
Graphics --> Probe[Loader exports / real framebuffer bytes]
Graphics --> Remaining[Compositor / content / Electron]
The Vulkan export regression caught C objects hidden behind lazy archive groups;
shared C/assembly units now link eagerly. The real SwiftShader pixel probe and
complete upstream suite pass at e42592d and the clean e677b62. Full Electron
remains unfinished.
- Complete upstream Linux source runtime; consume stable outputs here.
- Run the existing real sandboxed relocation smoke against that source runtime.
- Add OS metadata/protocol registration and distribution archives.
- Complete native execution validation and Electron-specific Node/V8 addon toolchains.
- Add signing/notarization and installers with explicit release credentials.
The example split transition builds Linux x86_64/ARM64, macOS ARM64 and Windows x86_64/ARM64 with GNU LLVM and MSVC. BB Linux executes every build action. One action verifies all seven binary architectures before emitting four native-host archives. GH downloads each using validated invocation metadata, CAS digests and a read-only BB key. GH hosted native runners only execute smoke; Linux ARM64 remains cross-build only. This follows the public formatjs/formatjs artifact handoff. See packaging parity.