Integration test: fbuild bloat end-to-end against FastLED master ESP32-S3 (Phase 2+3 prerequisite of #434)

[zackees]

Background

The Phase 2 + Phase 3 acceptance gate of #434. Captures the integration
test from the meta verbatim.

What to do

Add crates/fbuild-cli/tests/bloat_esp32s3_fastled_master.rs:

#[test]
#[ignore = \"network: fetches FastLED master + downloads esp-idf toolchain\"]
fn bloat_esp32s3_blink_fastled_master_end_to_end() {
 // 1. Materialise a fbuild project skeleton in a temp dir:
 // - platformio.ini selecting board=esp32s3
 // - src/main.cpp that #include <FastLED.h> + a NEOPIXEL blink loop
 // - lib_deps = \"https://github.com/FastLED/FastLED#master\"
 let project = TempProject::scaffold_esp32s3_blink_fastled_master();

 // 2. fbuild build . (uses fbuild's native esp32 orchestrator; no PIO)
 run_fbuild(&[\"build\", project.path()]).expect(\"fbuild build succeeded\");

 // 3. Verify build_info.json has the four toolchain paths (#428).
 let build_info = project.read_build_info(\"esp32s3\");
 assert!(!build_info[\"nm_path\"].as_str().unwrap().is_empty());
 assert!(!build_info[\"cppfilt_path\"].as_str().unwrap().is_empty());
 assert!(!build_info[\"readelf_path\"].as_str().unwrap().is_empty());
 assert!(!build_info[\"objdump_path\"].as_str().unwrap().is_empty());

 // 4. fbuild bloat . (no flags, no --nm)
 let bloat_stdout = run_fbuild(&[\"bloat\", project.path()])
 .expect(\"fbuild bloat succeeded\");

 // 5. Report files exist at the documented path.
 let report_dir = project.path().join(\".fbuild/build/esp32s3/bloat-report\");
 assert!(report_dir.join(\"report.json\").is_file());
 assert!(report_dir.join(\"report.md\").is_file());

 // 6. stdout prints both absolute paths on exit.
 assert!(bloat_stdout.contains(\"report.json\"));
 assert!(bloat_stdout.contains(\"report.md\"));

 // 7. Content invariants — bounds generous so FastLED master drift
 // doesn't flake the test.
 let report: serde_json::Value = serde_json::from_str(
 &std::fs::read_to_string(report_dir.join(\"report.json\")).unwrap()).unwrap();
 let total_flash = report[\"total_flash\"].as_u64().unwrap();
 let total_ram = report[\"total_ram\"].as_u64().unwrap();
 let symbols = report[\"symbols\"].as_array().unwrap();
 let sections = report[\"sections\"].as_array().unwrap();

 assert!((300_000..500_000).contains(&total_flash));
 assert!((25_000..60_000).contains(&total_ram));
 assert!(symbols.len() > 2_000);
 assert!(sections.len() > 100);

 // 8. Map-derived synthesis covered (#427 invariant).
 let synth_count = symbols.iter()
 .filter(|s| s[\"source\"].as_str() == Some(\"map-derived\"))
 .count();
 assert!(synth_count > 100);

 // 9. Markdown report renders a top-flash table.
 let md = std::fs::read_to_string(report_dir.join(\"report.md\")).unwrap();
 assert!(md.contains(\"# Symbol analysis\"));
 assert!(md.contains(\"## Top\"));
 assert!(md.contains(\"flash symbols\"));
 assert!(md.contains(\"| Bytes |\"));
 assert!(md.contains(\"fl::\"));
}

Infra

• #[ignore] by default so ordinary cargo test runs aren't
  network-dependent.
• Add a nightly CI matrix entry (workflow_dispatch + scheduled
  weekly) so FastLED master regressions surface here.
• Cache the esp-idf toolchain via the existing setup-soldr zccache
  flow — second run should be < 30 s.

Why pin FastLED master

Exercises the realistic case (latest FastLED, biggest binary, most
complex symbol graph). The >2000 symbols / >100 map-derived
invariants pin the shape of the report, not exact bytes.

Acceptance

• The test compiles + runs locally via cargo test --ignored bloat_esp32s3 once the network is available.
• It's green on the nightly esp32s3 + FastLED-master matrix for two
  consecutive weeks (the meta closes when this holds, per Meta: fbuild bloat — first-class, end-to-end bloat analysis with build_info-driven toolchain resolution (no manual nm/c++filt, no PlatformIO, no side scripts) #434).

Related

• Meta: fbuild bloat — first-class, end-to-end bloat analysis with build_info-driven toolchain resolution (no manual nm/c++filt, no PlatformIO, no side scripts) #434 (meta).
• fbuild bloat: rename 'symbols' subcommand + drop flag dependencies (Phase 2 of #434) #438 (Phase 2 — the bloat subcommand).
• fbuild bloat: default output dir under build tree + path printing on exit (Phase 3 of #434) #439 (Phase 3 — default output dir + exit path printing).

[zackees]

Shipped via merged PR #448.