Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

test_runner: adds built in lcov test reporter #50018

Merged
merged 14 commits into from
Oct 25, 2023
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 18 additions & 2 deletions doc/api/test.md
Original file line number Diff line number Diff line change
Expand Up @@ -403,6 +403,18 @@ if (anAlwaysFalseCondition) {
}
```

### Coverage reporters

The tap and spec reporters will print a summary of the coverage statistics.
There is also an lcov reporter that will generate an lcov file which can be
used as an in depth coverage report.

```bash
node --test --experimental-test-coverage --test-reporter=lcov --test-reporter-destination=lcov.info
```

### Limitations

The test runner's code coverage functionality has the following limitations,
which will be addressed in a future Node.js release:

Expand Down Expand Up @@ -850,6 +862,10 @@ The following built-reporters are supported:
* `junit`
The junit reporter outputs test results in a jUnit XML format

* `lcov`
philnash marked this conversation as resolved.
Show resolved Hide resolved
The `lcov` reporter outputs test coverage when used with the
[`--experimental-test-coverage`][] flag.

When `stdout` is a [TTY][], the `spec` reporter is used by default.
Otherwise, the `tap` reporter is used by default.

Expand All @@ -861,11 +877,11 @@ to the test runner's output is required, use the events emitted by the
The reporters are available via the `node:test/reporters` module:

```mjs
import { tap, spec, dot, junit } from 'node:test/reporters';
import { tap, spec, dot, junit, lcov } from 'node:test/reporters';
```

```cjs
const { tap, spec, dot, junit } = require('node:test/reporters');
const { tap, spec, dot, junit, lcov } = require('node:test/reporters');
```

### Custom reporters
Expand Down
107 changes: 107 additions & 0 deletions lib/internal/test_runner/reporter/lcov.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,107 @@
'use strict';

const { relative } = require('path');
const Transform = require('internal/streams/transform');

// This reporter is based on the LCOV format, as described here:
// https://ltp.sourceforge.net/coverage/lcov/geninfo.1.php
// Excerpts from this documentation are included in the comments that make up
// the _transform function below.
class LcovReporter extends Transform {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This can be written more cleanly with modern stream machinery but I'm 100% OK with landing and then refactoring.

constructor(options) {
super({ ...options, writableObjectMode: true, __proto__: null });
}

_transform(event, _encoding, callback) {
philnash marked this conversation as resolved.
Show resolved Hide resolved
if (event.type !== 'test:coverage') {
return callback(null);
}
let lcov = '';
// A tracefile is made up of several human-readable lines of text, divided
// into sections. If available, a tracefile begins with the testname which
// is stored in the following format:
// ## TN:\<test name\>
lcov += 'TN:\n';
const {
data: {
summary: { workingDirectory },
},
} = event;
try {
for (let i = 0; i < event.data.summary.files.length; i++) {
const file = event.data.summary.files[i];
// For each source file referenced in the .da file, there is a section
// containing filename and coverage data:
// ## SF:\<path to the source file\>
lcov += `SF:${relative(workingDirectory, file.path)}\n`;

// Following is a list of line numbers for each function name found in
// the source file:
// ## FN:\<line number of function start\>,\<function name\>
//
// After, there is a list of execution counts for each instrumented
// function:
// ## FNDA:\<execution count\>,\<function name\>
//
// This loop adds the FN lines to the lcov variable as it goes and
// gathers the FNDA lines to be added later. This way we only loop
// through the list of functions once.
let fnda = '';
for (let j = 0; j < file.functions.length; j++) {
const func = file.functions[j];
const name = func.name || `anonymous_${j}`;
benjamingr marked this conversation as resolved.
Show resolved Hide resolved
lcov += `FN:${func.line},${name}\n`;
fnda += `FNDA:${func.count},${name}\n`;
}
lcov += fnda;

// This list is followed by two lines containing the number of
// functions found and hit:
// ## FNF:\<number of functions found\>
// ## FNH:\<number of function hit\>
lcov += `FNF:${file.totalFunctionCount}\n`;
lcov += `FNH:${file.coveredFunctionCount}\n`;

// Branch coverage information is stored which one line per branch:
// ## BRDA:\<line number\>,\<block number\>,\<branch number\>,\<taken\>
// Block number and branch number are gcc internal IDs for the branch.
// Taken is either '-' if the basic block containing the branch was
// never executed or a number indicating how often that branch was
// taken.
for (let j = 0; j < file.branches.length; j++) {
lcov += `BRDA:${file.branches[j].line},${j},0,${file.branches[j].count}\n`;
}

// Branch coverage summaries are stored in two lines:
// ## BRF:\<number of branches found\>
// ## BRH:\<number of branches hit\>
lcov += `BRF:${file.totalBranchCount}\n`;
lcov += `BRH:${file.coveredBranchCount}\n`;

// Then there is a list of execution counts for each instrumented line
// (i.e. a line which resulted in executable code):
// ## DA:\<line number\>,\<execution count\>[,\<checksum\>]
const sortedLines = file.lines.toSorted((a, b) => a.line - b.line);
for (let j = 0; j < sortedLines.length; j++) {
lcov += `DA:${sortedLines[j].line},${sortedLines[j].count}\n`;
}

// At the end of a section, there is a summary about how many lines
// were found and how many were actually instrumented:
// ## LH:\<number of lines with a non-zero execution count\>
// ## LF:\<number of instrumented lines\>
lcov += `LH:${file.coveredLineCount}\n`;
lcov += `LF:${file.totalLineCount}\n`;

// Each sections ends with:
// end_of_record
lcov += 'end_of_record\n';
}
} catch (error) {
return callback(error);
}
return callback(null, lcov);
}
}

module.exports = LcovReporter;
1 change: 1 addition & 0 deletions lib/internal/test_runner/utils.js
Original file line number Diff line number Diff line change
Expand Up @@ -112,6 +112,7 @@ const kBuiltinReporters = new SafeMap([
['dot', 'internal/test_runner/reporter/dot'],
['tap', 'internal/test_runner/reporter/tap'],
['junit', 'internal/test_runner/reporter/junit'],
['lcov', 'internal/test_runner/reporter/lcov'],
]);

const kDefaultReporter = process.stdout.isTTY ? 'spec' : 'tap';
Expand Down
10 changes: 10 additions & 0 deletions lib/test/reporters.js
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ let dot;
let junit;
let spec;
let tap;
let lcov;

ObjectDefineProperties(module.exports, {
__proto__: null,
Expand Down Expand Up @@ -45,4 +46,13 @@ ObjectDefineProperties(module.exports, {
return tap;
},
},
lcov: {
__proto__: null,
configurable: true,
enumerable: true,
get() {
lcov ??= require('internal/test_runner/reporter/lcov');
return ReflectConstruct(lcov, arguments);
},
},
});
7 changes: 7 additions & 0 deletions test/fixtures/test-runner/output/lcov_reporter.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
'use strict';
require('../../../common');
const fixtures = require('../../../common/fixtures');
const spawn = require('node:child_process').spawn;

spawn(process.execPath,
['--no-warnings', '--experimental-test-coverage', '--test-reporter', 'lcov', fixtures.path('test-runner/output/output.js')], { stdio: 'inherit' });
Loading