`all: true` is ignored — coverage report only includes imported files; CLI `c8 --all` works on the same data

[emersonjds]

Summary

When configuring @pokujs/c8 with all: true and src: ['src'], the final coverage report only contains files that were imported by tests. Files inside src/ that were never required at runtime are silently omitted, producing a misleading high-coverage number.

Running the standalone c8 CLI on the very same NODE_V8_COVERAGE directory does include the uncovered files (and reports them as 0%), so the V8 coverage data is fine — the issue seems to be in how the plugin propagates all / src to c8's Report (or in how globs are resolved).

Environment

Node	v24.14.0
poku	4.3.0
@pokujs/c8	1.2.0
c8	10.1.3
OS	macOS Darwin 25.5.0 (arm64)

Minimal reproduction

repro/
├── package.json
├── poku.config.mjs
└── src/
    ├── covered.ts                        # imported by test
    ├── never-imported.ts                 # NOT imported anywhere
    └── __tests__/covered.test.ts

package.json:

{
  "type": "module",
  "scripts": { "test": "poku --coverage" },
  "devDependencies": {
    "poku": "4.3.0",
    "@pokujs/c8": "1.2.0",
    "c8": "10.1.3",
    "tsx": "^4.21.0"
  }
}

poku.config.mjs:

import { defineConfig } from 'poku';
import { coverage } from '@pokujs/c8';

export default defineConfig({
  parallel: true,
  concurrency: 4,
  include: ['src/**/__tests__'],
  plugins: [
    coverage({
      requireFlag: true,
      all: true,
      src: ['src'],
      include: ['src/**/*.ts', 'src/**/*.tsx'],
      exclude: ['src/**/__tests__/**', 'src/**/*.d.ts'],
      extension: ['.ts', '.tsx'],
      reporter: ['text'],
    }),
  ],
});

src/covered.ts:

export const sum = (a: number, b: number) => a + b;

src/never-imported.ts:

export const noop = () => null;
export const greet = (name: string) => `hi ${name}`;

src/__tests__/covered.test.ts:

import { test, assert } from 'poku';
import { sum } from '../covered';

await test('sum', () => assert.strictEqual(sum(2, 3), 5));

Steps

npx poku --coverage

Actual output (incorrect)

File         | % Stmts | % Branch | % Funcs | % Lines
covered.ts   |  100    |  100     |  100    |  100

never-imported.ts is missing from the report despite all: true and src: ['src'].

Expected output

never-imported.ts should appear with 0% coverage (this is the documented behavior of c8 --all).

Workaround proving the V8 data is correct

Capture NODE_V8_COVERAGE to a fixed dir and run the c8 CLI on the same data:

rm -rf /tmp/cov && mkdir /tmp/cov
NODE_V8_COVERAGE=/tmp/cov npx poku
npx c8 report \
  --reporter=text-summary \
  --include='src/**/*.ts' --include='src/**/*.tsx' \
  --exclude='src/**/__tests__/**' \
  --extension=.ts --extension=.tsx \
  --all --src=src \
  --temp-directory=/tmp/cov

Output (correct, includes uncovered files):

=============================== Coverage summary ===============================
Statements   : 33.33% (3/9)
Branches     : 100% (0/0)
Functions    : 33.33% (1/3)
Lines        : 33.33% (3/9)
================================================================================

Possible cause

Looking at node_modules/@pokujs/c8/lib/index.js, the constructor call to c8's Report propagates all and src:

const report = Report({
  tempDirectory: tempDir,
  reportsDirectory,
  reporter,
  include: options.include ?? [],
  exclude: options.exclude,
  extension: options.extension,
  all: options.all ?? false,
  src: options.src,
  resolve: '',
  // ...
});

So all: true should reach Report. Inside c8, _includeUncoveredFiles (node_modules/c8/lib/report.js:400) does this.exclude.globSync(workingDir).forEach(...) and filters by extension.includes(ext). The fact that the standalone CLI works on identical data points to one of:

1. The include glob format passed by the plugin (['src/**/*.ts', 'src/**/*.tsx']) is interpreted differently than the equivalent --include flags by test-exclude once it goes through Report constructed programmatically.
2. The extension array is being passed in a form the plugin path doesn't honor (e.g., the CLI normalizes --extension=.ts differently than passing ['.ts'] programmatically).
3. The tempDirectory ends up split across multiple per-process dirs and only the main process's dir is read by the plugin's Report, while c8 report --temp-directory=/tmp/cov reads everything.

I'd start by reproducing with DEBUG=c8 npx poku --coverage and logging tempDir, options.all, options.src, and the result of the internal Exclude.globSync(workingDir) call.

Impact

Coverage thresholds via the plugin are unreliable: a project with 5% real coverage shows 98%+ because only loaded modules count. CI gates can't depend on the plugin output today; users have to run c8 report --all ... as a post-step (which defeats the purpose of having a plugin).

[wellwelwel]

@emersonjds, can you check if this also happens with c8 alone (without @pokujs/coverage)? I'm asking this because of this PR I opened in c8 itself fixing this similar issue:

• fix: include uncovered files in report when using --all with --include bcoe/c8#589
• Coverage report is missing uncovered files when using --all with --include bcoe/c8#588

[emersonjds]

Hi @wellwelwel — thanks for looking into this and for the pointer to bcoe/c8#588 or bcoe/c8#589

No, the issue does not reproduce with c8 alone. Both the CLI and the programmatic Report() API work correctly. The bug is inside @pokujs/c8 itself apparently.

Environment

Node v24.14.0 · c8 10.1.3 · @pokujs/c8 1.2.0 · macOS Darwin 25.5.0 arm64

Reproduction

Step 1 — generate raw V8 coverage without the plugin:

rm -rf /tmp/poku-cov && mkdir /tmp/poku-cov
NODE_V8_COVERAGE=/tmp/poku-cov npx poku

Step 2 — consume the same JSON via the c8 CLI:

npx c8 report \
--reporter=text-summary
--include='src//*.ts' \
--include='src//*.tsx'
--exclude='src//tests/' \
--extension=.ts --extension=.tsx
--all --src=src \
--temp-directory=/tmp/poku-cov

Step 3 — consume the same JSON via the programmatic Report() API:

// test-c8-api.mjs
import { createRequire } from 'node:module';
const require = createRequire(import.meta.url);
const Report = require('c8/lib/report.js');

const report = Report({
tempDirectory: '/tmp/poku-cov',
reporter: ['text-summary'],
include: ['src//*.ts', 'src//*.tsx'],
exclude: ['src//tests/'],
extension: ['.ts', '.tsx'],
all: true,
src: ['src'],
resolve: '',
});

await report.run();

Result

Both paths produced identical output:

• Statements: 16.3% — 1788 / 10966
• Branches: 74.01% — 302 / 408
• Functions: 43.2% — 54 / 125
• Lines: 16.3% — 1788 / 10966

Uncovered files are included as expected. For comparison, the same data routed through @pokujs/c8 reports only ~600
statements (imported files only).

Conclusion

c8 handles all: true + include correctly in both scenarios. The discrepancy only appears when going through @pokujs/c8.
Since the parameters passed to Report() inside the plugin look correct (I checked lib/index.js), the issue is likely in
how the plugin wires the subprocess environment before the Report() call — not in c8 itself.

So this seems unrelated to bcoe/c8#588 or bcoe/c8#589.

[wellwelwel]

Hey @emersonjds! I looked at your code to reproduce the problem, but I couldn't and 100% of the time it worked perfectly.

What seems to be happening is that you are using the script poku --coverage, but using a configuration file that Poku doesn't look for, therefore being ignored.

When using the --coverage flag, Poku will use the default settings of the plugin (@pokujs/c8, in this case), which explains the behavior you reported. To use the .mjs extension, you must use the command like poku -c=poku.config.mjs --coverage or, since the project is already "type": "module", you can just rename the configuration file ext to .js 🙋🏻‍♂️

[emersonjds]

Hey @emersonjds! I looked at your code to reproduce the problem, but I couldn't and 100% of the time it worked perfectly.

What seems to be happening is that you are using the script poku --coverage, but using a configuration file that Poku doesn't look for, therefore being ignored.

When using the --coverage flag, Poku will use the default settings of the plugin (@pokujs/c8, in this case), which explains the behavior you reported. To use the .mjs extension, you must use the command like poku -c=poku.config.mjs --coverage or, since the project is already "type": "module", you can just rename the configuration file ext to .js 🙋🏻‍♂️

Thanks! Renaming to .js did the trick. Everything is working as expected now.

Really appreciate the help from the poku team! 🙌