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Phase 30. mochi-runtime gem unit tests + gem-build CI (audit-5)

FieldValue
MEPMEP-56 §Phases
StatusLANDED
Started2026-05-29 14:13 (GMT+7)
Landed2026-05-29 14:13 (GMT+7)
Tracking issue—
Tracking PR#22510
Commitc1fe1b55ef

Gate​

Two new CI steps land alongside four new minitest files. The phase is green when all four steps below pass on each Ruby matrix entry (CRuby 3.2 / 3.4 on ubuntu, CRuby 3.4 on macos):

  1. ruby -Ilib -Itest test/test_version.rb (3 runs / 5 assertions): VERSION defined, SemVer-shaped (/\A\d+\.\d+\.\d+\z/), frozen (matches frozen_string_literal: true).
  2. ruby -Ilib -Itest test/test_io.rb (7 runs / 16 assertions): format_value of int / fractional float / integer-valued float / nil / bool / string / Unicode; putln writes formatted value + newline to $stdout.
  3. ruby -Ilib -Itest test/test_panic.rb (5 runs / 7 assertions): Panic inherits from StandardError; carries code and message; round-trips through rescue Mochi::Runtime::Panic => e; does not capture unrelated errors; code is read-only.
  4. ruby -Ilib -Itest test/test_stream.rb (6 runs / 14 assertions): subscribe receives emitted values in order; late subscribers miss prior emits; multiple subscribers each get the full stream; subscribe_limit(N) silently drops past N; LimitedQueue.pop blocks until push; LimitedQueue silently drops above limit.
  5. gem build mochi-runtime.gemspec succeeds and produces mochi-runtime-<version>.gem.

Local run before commit: 21 runs / 42 assertions / 0 failures. Each .rb test file uses only stdlib minitest/autorun and the targeted lib file via require_relative, so the suite has zero external dependencies.

Build target / audit decisions​

The phase does not change build.go, the lower pass, or the runtime gem code. Three audit decisions are baked into the test design:

  1. Stdlib minitest, no Rakefile, no Gemfile. The runtime gem stays a flat-file project: tests live under mochi-runtime/test/, each is runnable as a standalone script via ruby -Ilib -Itest test/test_X.rb. This keeps the gem trivial to build from a release artefact (no bundle install step in downstream consumers) and keeps the CI step explicit (one line per test file, no test-discovery magic).
  2. gem build validation belongs in CI, not in the transpiler test suite. Phase 22 (TargetRubyGem) only validates the gemspec we generate for the user via Driver.Build; the runtime gem's own mochi-runtime.gemspec is consumed via require_relative in every test and is implicitly trusted. Phase 30 adds an explicit gem build mochi-runtime.gemspec so a future regression (missing files in files, bad metadata, dropped dependency) fails fast in CI rather than at publish time.
  3. Test the public contract that emitted Mochi code depends on. Each test covers a behaviour that the transpiler's emit layer assumes: format_value's float formatting (used by print(float) in phase 02), Panic#code round-trip (used by try/catch in phase 19), Stream ordering (used by phase 13), subscribe_limit drop semantics (used by phase 21). A regression in any of these would silently break the corresponding transpiler phase output.

Files changed​

FilePurpose
mochi-runtime/test/test_version.rb3 runs / 5 assertions: VERSION defined, SemVer-shaped, frozen
mochi-runtime/test/test_io.rb7 runs / 16 assertions: format_value over scalars + Unicode; putln to $stdout
mochi-runtime/test/test_panic.rb5 runs / 7 assertions: Panic is StandardError, carries code+message, rescuable, read-only code
mochi-runtime/test/test_stream.rb6 runs / 14 assertions: Stream ordering, late-subscriber miss, multi-sub, subscribe_limit drop, LimitedQueue push/pop semantics
.github/workflows/transpiler3-ruby-test.ymlTwo new steps: "Run mochi-runtime gem unit tests" runs all four minitest files; "Validate mochi-runtime.gemspec packs cleanly" runs gem build and lists the artefact
website/docs/implementation/0056/index.mdPhase 30 row appended to phases table
website/docs/implementation/0056/phase-30-runtime-gem-tests.mdThis tracking page
website/sidebars.jsPhase 30 entry appended after phase 29

Test set​

mochi-runtime/test/:

  • test_version.rb: test_version_constant_is_defined, test_version_is_semver_shaped, test_version_is_frozen.
  • test_io.rb: test_format_int, test_format_float_integer_valued_gets_dot_zero, test_format_float_fractional, test_format_nil_renders_empty, test_format_bool, test_format_string_round_trips, test_putln_writes_to_stdout_with_newline.
  • test_panic.rb: test_panic_is_standard_error, test_panic_carries_code_and_message, test_panic_round_trip_through_rescue, test_panic_does_not_rescue_other_errors, test_panic_code_is_read_only.
  • test_stream.rb: test_subscribe_receives_emitted_values_in_order, test_late_subscriber_misses_prior_values, test_multiple_subscribers_each_get_full_stream, test_subscribe_limit_drops_after_threshold, test_limited_queue_pop_blocks_until_push, test_limited_queue_silently_drops_above_limit.

Closeout notes​

Phase 30 was the audit-5 follow-up to phase 29's CI matrix. Phase 29 surfaced that the runtime gem had zero direct unit tests and zero gem build validation in CI; phase 30 fixes both. The 21 minitest runs use only stdlib minitest/autorun so no Gemfile, bundler-cache, or rake setup is required, keeping the CI step diff under 20 lines. LimitedQueue.pop is intentionally tested with a real Thread.new + 10ms sleep rather than mocked, because the underlying contract is that pop blocks, and a mocked queue would not catch a regression that replaced the blocking Thread::Queue with a polling alternative.