Demonstrates how all coverage stats computed by c8 remain 100 if excludeAfterRemap is set to true. Contains files from the original project, which need only c8 to test.
How to test it:
# install dependencies and prepare coverage/tmp/out.json
npm ci
# run report with no exclusions
npx c8 report
# run report excluding src/codejar and src/prism
npm c8 report -a
npx c8 report reveals an incomplete coverage in script-editor.js, among other files:
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------------|---------|----------|---------|---------|-------------------
script-editor.js | 96.84 | 100 | 100 | 96.84 | 71-76
...
npm c8 report -a excludes other files with missing coverage, but the remaining script-editor.js is reported with the complete coverage:
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------------|---------|----------|---------|---------|-------------------
script-editor.js | 100 | 100 | 100 | 100 |
...
This project demonstrates computing the test code coverage only for a part of sources. The source files are located in the src directory:
src
├── bundled-engine.js
├── codejar
│ └── codejar.js
├── graph.js
├── index.js
├── prism
│ ├── prism-core.js
│ ├── prism-graphviz.js
│ ├── prism-line-highlight.js
│ ├── prism-line-numbers.js
│ └── prism-match-braces.js
├── renderer.js
├── script-editor.js
└── separate-engine.js
The minified bundles with source maps are located in the dist directory:
dist
├── index-bundled.min.js
├── index-bundled.min.js.map
├── index.min.js
├── index.min.js.map
├── renderer.min.js
└── renderer.min.js.map
The minified bundles refer to their source maps on their last line, for example, from index.min.js:
//# sourceMappingURL=index.min.js.map
The source map files include relative source file paths from dist to src, for example: ../src/graph.js.
The text code coverage produced using Puppeteer Coverage API is saved in data/out.json, where the absolute paths to the project root are replaced with $$$CWD$$$. The script data/prepare.js, which is executed during the prepare phase of npm ci, reads the JSON file, replaces the $$$CWD$$$ strings with the absolute path to the current project root and writes the result to converage/tmp/out.json. This simulates the state after collecting the test coverage in the original project.
The original project can be used to demonstrate the problem too:
git clone https://github.com/prantlf/graphviz-webcomponent.git
cd graphviz-webcomponent
git checkout c8-ethernal-100-coverage
npm i -g pnpm
pnpm i
npm test
npx c8 report -a
The exclusions from package.json do not apply, because they do not match the paths to the bundles loaded by the test pages:
"c8": {
"exclude": [
"src/codejar",
"src/prism"
],
...
}
The report includes all files, as expected:
❯ npx c8 report
-------------------------------------------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
-------------------------------------------------|---------|----------|---------|---------|-------------------
All files | 90.74 | 67.85 | 47.46 | 90.74 |
[email protected]/node_modules/@hpcc-js/wasm/dist | 100 | 59.16 | 40.68 | 100 |
graphviz.js | 100 | 59.16 | 40.68 | 100 | 1
src | 98.4 | 100 | 100 | 98.4 |
bundled-engine.js | 100 | 100 | 100 | 100 |
graph.js | 100 | 100 | 100 | 100 |
renderer.js | 100 | 100 | 100 | 100 |
script-editor.js | 96.84 | 100 | 100 | 96.84 | 71-76
separate-engine.js | 100 | 100 | 100 | 100 |
src/codejar | 100 | 70 | 30 | 100 |
codejar.js | 100 | 70 | 30 | 100 | 4-17
src/prism | 83.56 | 78.72 | 59.25 | 83.56 |
prism-core.js | 78.75 | 73.13 | 68.42 | 78.75 | ...48-252,322-325
prism-graphviz.js | 100 | 100 | 100 | 100 |
prism-line-numbers.js | 98.19 | 86.66 | 75 | 98.19 | 147-149
prism-match-braces.js | 82.58 | 100 | 0 | 82.58 | ...53,57-61,65-75
-------------------------------------------------|---------|----------|---------|---------|-------------------
ERROR: Coverage for lines (90.74%) does not meet global threshold (100%)
ERROR: Coverage for functions (47.46%) does not meet global threshold (100%)
ERROR: Coverage for branches (67.85%) does not meet global threshold (100%)
ERROR: Coverage for statements (90.74%) does not meet global threshold (100%)
Note the following line:
script-editor.js | 96.84 | 100 | 100 | 96.84 | 71-76
The exclusions from package.json do apply, because the -a command-line argument makes c8 match the excluded paths to sources from the source maps, as if excludeAfterRemap was set to true in package.json:
"c8": {
"excludeAfterRemap": true,
"exclude": [
"src/codejar",
"src/prism"
],
...
}
The report doesn't include excluded files, as expected, but the code coverage of the remaining files is always 100, also for files, have obviously less code coverages, as tested by disabling the exclusions:
❯ npx c8 report -a
--------------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
bundled-engine.js | 100 | 100 | 100 | 100 |
graph.js | 100 | 100 | 100 | 100 |
renderer.js | 100 | 100 | 100 | 100 |
script-editor.js | 100 | 100 | 100 | 100 |
separate-engine.js | 100 | 100 | 100 | 100 |
--------------------|---------|----------|---------|---------|-------------------
Note the following line:
script-editor.js | 100 | 100 | 100 | 100 |
Copyright (c) 2023 Ferdinand Prantl
Licensed under the MIT license.