deno coverage - Denoland

Inclusions and Exclusions

By default coverage includes any of your code that exists on the local file system, and it's imports.

You can customize the inclusions and exclusions by using the --include and --exclude options.

You can expand the coverage to include files that are not on the local file system by using the --include option and customizing the regex pattern.

bash

deno coverage --include="^file:|https:"

The default inclusion pattern should be sufficient for most use cases, but you can customize it to be more specific about which files are included in your coverage report.

Files that contain test.js, test.ts, test.jsx, or test.tsx in their name are excluded by default.

This is equivalent to:

bash

deno coverage --exclude="test\.(js|mjs|ts|jsx|tsx)$"

This default setting prevents your test code from contributing to your coverage report. For a URL to match it must match the include pattern and not match the exclude pattern.

Ignoring Code

Code can be ignored in generated coverage reports by adding coverage ignore comments. Branches and lines in ignored code will be excluded from the report. Ignored branches and lines do not count as covered lines. Instead, ignored lines of code are treated as empty lines.

To ignore an entire file, add a // deno-coverage-ignore-file comment at the top of the file.

// deno-coverage-ignore-file

// all code in this file is ignored

Ignored files will not appear in the coverage report.

To ignore a single line, add a // deno-coverage-ignore comment on the line above the code you want to ignore.

// deno-coverage-ignore
console.log("this line is ignored");

To ignore multiple lines, add a // deno-coverage-ignore-start comment above the code you want to ignore and a // deno-coverage-ignore-stop comment below.

// deno-coverage-ignore-start
if (condition) {
  console.log("both the branch and lines are ignored");
}
// deno-coverage-ignore-stop

All code after a // deno-coverage-ignore-start comment is ignored until a // deno-coverage-ignore-stop is reached.

Each // deno-coverage-ignore-start comment must be terminated by a // deno-coverage-ignore-stop comment, and ignored ranges may not be nested. When these requirements are not met, some lines may be unintentionally included in the coverage report. The deno coverage command will log warnings for any invalid comments.

// deno-coverage-ignore-start
if (condition) {
  // deno-coverage-ignore-start - A warning will be logged because the previous
  //                              coverage range is unterminated.
  console.log("this code is ignored");
  // deno-coverage-ignore-stop
}
// deno-coverage-ignore-stop

// ...

// deno-coverage-ignore-start - This comment will be ignored and a warning will
//                              be logged, because this range is unterminated.
console.log("this code is not ignored");

Only white space may precede the coverage directive in a coverage comment. However, any text may trail the directive.

// deno-coverage-ignore Trailing text is allowed.
console.log("This line is ignored");

// But leading text isn't. deno-coverage-ignore
console.log("This line is not ignored");

Coverage comments must start with //. Comments starting with /* are not valid coverage comments.

// deno-coverage-ignore
console.log("This line is ignored");

/* deno-coverage-ignore */
console.log("This line is not ignored");

Output Formats

By default we support Deno's own coverage format - but you can also output coverage reports in the lcov format (a standard file format used to describe code coverage data), or in html.

bash

deno coverage --lcov --output=cov.lcov

This lcov file can be used with other tools that support the lcov format.

bash

deno coverage --html

This will output a coverage report as a html file

Examples

Generate a coverage report from the default coverage profile in your workspace

bash

deno test --coverage
deno coverage

Generate a coverage report from a coverage profile with a custom name

bash

deno test --coverage=custom_profile_name
deno coverage custom_profile_name

Note: You can alternatively set coverage directory by DENO_COVERAGE_DIR env var.
DENO_COVERAGE_DIR=custom_profile_name deno test
deno coverage custom_profile_name

Only include coverage that matches a specific pattern - in this case, only include tests from main.ts

bash

deno coverage --include="main.ts"

Export test coverage from the default coverage profile to an lcov file

bash

deno test --coverage
deno coverage --lcov --output=cov.lcov