Run the runtime tests that never ran and drop dead test code

[cristianoc]

Part of #8712.

Summary

• Remove unused bindings from the docstring tests' Node module. Path.join2, Process.cwd/argv/exit/env, Fs.existsSync/mkdirSync/ writeFileSync/readFileSync, ChildProcess.execSync and the top-level import.meta.dirname external are used by neither DocTest.res nor SpawnAsync.res (DocTest derives its directory from import.meta.url). Externals emit no JavaScript, so Node.res.js is unchanged.
• Run the stdlib String and dynamic-import tests. Stdlib_StringTests and Stdlib_ImportTests hold Test.run assertions, but no entry point included them, so they never executed; Stdlib_TestSuite now includes both (they pass).
• Make a failing stdlib Test.run fail the test process. Test.run only logged a failure, so node Stdlib_TestSuite.mjs exited 0 and scripts/test.js passed regardless; it now sets process.exitCode to 1, so the remaining assertions still run and the suite fails at exit. The unused process.exit external is gone. All current assertions pass; a deliberately failing one makes the suite exit 1.
• Name the unloaded mocha suites _test so mocha runs them. scripts/test.js runs mocha on tests/tests/src/*/*_test.mjs, so the describe blocks in arity_deopt, bs_ignore_effect, inline_map_demo, int_poly_var, recursive_module, test_case_opt_collision, test_for_of, test_string_const, test_zero_nullable and tramp_fib never ran. Each is renamed to a *test name (recursive_module2_test, since recursive_module_test exists; the test prefix is dropped where the suffix is added) and its regenerated .mjs committed; the module name and LOC strings change with the file name. All 22 tests pass (mocha 580 passing, from 558).
• Remove the unused approxEq test helpers. Test_utils.approxEq in tests/tests/src and tests/belt_tests/src has no caller in either suite; the tests/tests copy's doc comment also said it returns a bool, while it asserts. Their compiled test_utils.mjs lose the export.
• Remove duplicate codegen snapshot tests. Each removed source repeats another test's program: DerivingAccessorsUncurried is DerivingAccessorsCurried plus a no-op @@uncurried (byte-identical .mjs); conditional/cond_c equals cond_b and cond_a_C equals cond_a_B up to the module name; test_u is test_fib.res:54-62; test_eq is the first line of test_ari.res; belt test_for_map is test_for_map2 up to the alias name. None is imported by another test.
• Remove test sources that hold only comments. gpr_441.res, gpr_1759_test.res and gpr_4494_test.res are entirely commented out, and debug_tmp.res is a @@config with commented-out code; each compiles to the empty-output stub and nothing imports them.
• Remove stale comments from tests/tests sources. The removed comments state what the code no longer does: DotDotDot's commented-out spread parses and compiles; bs_auto_uncurry's arity-adjust wrapper and a_scope_bug's even$1 renaming are absent from the committed .mjs; pipe_send_readline has no [@@bs.xx]; test_literal compiles; test_dup_param shows duplicate parameters compile in strict mode (test_seq's FIXME); test_pervasive and test_string_case carried OCaml compile-command footers. int_overflow_test's hex comments were swapped. No .mjs changes.
• Fix test assertions and labels that disagree with their code. float_test checked generic_lessequal against nan twice per order and float_lessequal never; it now checks each once. optional_ffi_test's second pair read counter instead of counter2, the ref bug_to_fix2 updates. flexible_array_test computed the 500-element sort comparison and discarded it; it is now asserted. Labels: Stdlib_PromiseTest "value should be 5" asserts 10, string_const_test "getUnsafe" tests codePointAt, belt_list_test had a "droo" test and two named "makeBy". Belt comments: list_test called a five-int list a tuple, ticker's doc said sort_uniq where the code sorts, and bs_map_set_dict_test claimed assertions above that only log. All pass (mocha 580, stdlib suite).
• Remove gpr_2789_test, which asserts only 1 = 1. Its one mocha test is named "weak array commented out tests" and says the tests are commented out, but the file holds no commented-out tests: its only assertion is eq(LOC, 1, 1), and nothing imports it.
• Remove the unused notDeepEqual binding from tests/tests node_assert. No tests/tests source calls Node_assert.notDeepEqual or aliases the module. The binding is an external, so node_assert.mjs is unchanged.

Test plan

• dune build
• dune build @fmt
• dune build --profile browser @check
• make
• make lib
• no change in the runtime and Belt lib/ outputs
• make test
• make test-analysis
• make test-tools
• make test-gentype
• make test-syntax
• make checkformat
• npm run check

🤖 Generated with Claude Code

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-02T06:34:27.212721Z	8d6173d	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 8d6173d71d

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Invoke the dynamic-import test instead of only importing it

Including this module still does not run its assertion: Stdlib_ImportTests.res ends with main->ignore, which ignores the async function value rather than calling it, and the generated Stdlib_ImportTests.mjs only exports main without invoking it. Consequently, when scripts/test.js executes Stdlib_TestSuite.mjs, the newly included dynamic-import test remains untested; call main() (and retain/await its promise as appropriate) from the suite or module.

Useful? React with 👍 / 👎.

[cristianoc]

Confirmed: main->ignore discarded the async function, so the dynamic-import assertion never ran (changing the expected value to 2 still left node tests/tests/src/stdlib/Stdlib_TestSuite.mjs at exit 0). 9419b6d calls main()->ignore, and the regenerated .mjs now invokes main() at module load; Test.run sets process.exitCode = 1 on failure, so the same broken assertion now prints the failure and exits 1. The existing assertion in Stdlib_ImportTests.res is the test that now runs.

[pkg-pr-new]

Open in StackBlitz

rescript

npm i https://pkg.pr.new/rescript@8710

@rescript/belt

npm i https://pkg.pr.new/@rescript/belt@8710

@rescript/darwin-arm64

npm i https://pkg.pr.new/@rescript/darwin-arm64@8710

@rescript/darwin-x64

npm i https://pkg.pr.new/@rescript/darwin-x64@8710

@rescript/linux-arm64

npm i https://pkg.pr.new/@rescript/linux-arm64@8710

@rescript/linux-x64

npm i https://pkg.pr.new/@rescript/linux-x64@8710

@rescript/runtime

npm i https://pkg.pr.new/@rescript/runtime@8710

@rescript/win32-x64

npm i https://pkg.pr.new/@rescript/win32-x64@8710

commit: 9419b6d

[github-actions]

Developer playground preview: https://rescript-lang.github.io/rescript/dev-playground/?version=pr-8710

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.19%. Comparing base (ece8b14) to head (9419b6d).
⚠️ Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8710      +/-   ##
==========================================
+ Coverage   78.67%   79.19%   +0.51%     
==========================================
  Files         476      473       -3     
  Lines       64402    64011     -391     
==========================================
+ Hits        50670    50691      +21     
+ Misses      13732    13320     -412     

see 99 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.