# Testing > Run JavaScript and TypeScript `node:test` files and JUnit tests with `elide test`: discovery, selecting tests, options, reports and coverage. `elide test` runs JavaScript and TypeScript `node:test` files and JUnit tests. ```bash elide test ``` A failing test makes the exit code non-zero. Discovering and running JavaScript tests with Elide ## JavaScript and TypeScript Tests use the `node:test` API and need no manifest. A file is a test if it matches `*.test.*`, `*.spec.*`, `*_test.*` or `*_spec.*`, or is under `test`, `tests` or `__tests__`. Extensions: `.js`, `.mjs`, `.cjs`, `.ts`, `.mts`, `.cts`. Discovery skips hidden, dependency and build-output directories. It stops at any nested project (a directory with `elide.pkl`, `package.json`, `pom.xml` or `requirements.txt`), so a workspace root finds no member tests. Name a path to run them. ```js import test from "node:test"; import assert from "node:assert"; test("adds two values", () => { assert.equal(1 + 1, 2); }); ``` ## JVM tests JVM tests run on the JUnit Platform and need an `elide.pkl`. `src/test` is the default test source set; a declared source set of type `test` replaces it ([Source Sets](https://elide.help/docs/toolchain/source-sets)). - Test sets get `testPackages` plus the main set's dependencies. - Bundled JUnit libraries are added by default. `jvm.features.testing = false` removes both the JUnit compile APIs and the bundled runtime; a JVM test run then needs a JUnit console launcher (`junit-platform-console`) in `testPackages`, and fails with an error otherwise. Runs that include no JVM tests are unaffected. - `processors` run on test sources. - The test JVM gets `jvm.flags` and `jvm.defs` (as `-D`). - `modules` dependencies of the test and main sets go on `--module-path` with `--add-modules=ALL-MODULE-PATH`. - Parallel settings in a `junit-platform.properties` on the test classpath override `--concurrency`. ## Select tests Paths, directories or globs narrow JavaScript and TypeScript tests: ```bash elide test src/api elide test src/api/client.test.ts ``` Path arguments skip JVM tests and print `Path filtering unsupported for JVM tests: `. `-t` matches test names in both runners: ```bash elide test -t 'parses .+ headers' ``` JVM tests take JUnit selectors and tag expressions: ```bash elide test --select=class:com.example.ParserTest elide test --select=method:com.example.ParserTest#parsesHeaders elide test --select=package:com.example.parser # the package and its subpackages elide test com.example.parser # a dotted bare token is a package selector elide test --include-tag=fast --include-tag=unit # fast OR unit elide test --exclude-tag=slow --exclude-tag=flaky # neither slow nor flaky elide build test --select=class:com.example.ParserTest ``` elide test — JUnit selectors on a Kotlin project `--include-tag='slow & !flaky'` is one expression. Tag filters apply after selectors. ## Output and reports Progress goes to stderr; the final tally goes to stdout: ```bash elide test > summary.txt elide test 2> progress.txt ``` Reporters write to `.dev/reports/tests///`. `testing.reports` in `elide.pkl` turns them on without a flag: ```pkl import "elide:Testing.pkl" as Testing testing { reports { Testing.xmlReport() } } ``` ### TAP output `--reporter=tap` makes stdout a pure TAP 13 stream: ```text TAP version 13 # start 1: suite A > t1 # out 1: printed from inside a test ok 1 - suite A > t1 # start 2: broken not ok 2 - broken --- message: "expected 1 to equal 2" severity: "ERR_ASSERTION" ... 1..2 ``` - `# start ` opens a test; its output lines are `# out : `. `# out: ` belongs to no test. - Test points are numbered `1..N` in finishing order. Match points to tests by the `# start` line, not the number. - A YAML block appears only on failures with details; `severity` is the runner's error code, if any. - Stderr is not framed: `elide test --reporter=tap 2>&1` is not valid TAP. - JVM: output is tagged with its test only while exactly one test runs. With `--concurrency` above 1 or a project `junit-platform.properties`, it is untagged. - JavaScript: `console.log` inside a test, or at top level after importing `node:test`, is framed. Output before that import is raw. Hook output belongs to the test the hook wraps; `t.diagnostic` is framed as `# out`. ## Coverage ```bash elide test --coverage elide run --coverage ``` JVM coverage goes to `.dev/reports/coverage/jvm//` as HTML, XML or CSV; JavaScript and TypeScript coverage is LCOV, in `.dev/reports/coverage/js/lcov.info` for tests and `.dev/reports/coverage/js/run/lcov.info` for runs. The console prints one combined summary. The top-level `coverage` block collects without the flag: ```pkl import "elide:Coverage.pkl" as Coverage coverage { enabled = true scope = "tests" jvm { excludes { "org.example.generated.*" } reports { Coverage.xmlReport() Coverage.htmlReport() } } js { paths { "src" } } } ``` | Property | Meaning | Default | | --- | --- | --- | | `enabled` | Collect without `--coverage`. | `false` | | `scope` | `"tests"`, `"runs"` or `"all"`; `--coverage` always covers its own task. | `"tests"` | | `jvm.reports` | `Coverage.htmlReport()`, `xmlReport()`, `csvReport()`. | none | | `jvm.excludes` | Class patterns (`*`, `?`) not instrumented, such as generated code. | none | | `js.paths` | Source roots to report; empty means the whole project. | none | With coverage, `elide run` starts a separate JVM process. ## Options | Option | Effect | | --- | --- | | `-t REGEX` | Match test or enclosing-suite names. | | `--where CEL` | JavaScript: run tests for which a [CEL](https://elide.help/docs/api-cel) expression over `name`, `parents` and `file` is true. | | `--select=SELECTOR` | JVM: `class:`, `method:` or `package:` selector; repeatable. | | `--include-tag=EXPR` | JVM: run tests whose tags match; repeats are ORed. | | `--exclude-tag=EXPR` | JVM: skip tests whose tags match; repeats are ANDed. | | `--bail[=N]` | Stop after `N` failures (default 1). | | `--test-timeout=MS` | Default per-test timeout. | | `--timeout DURATION` | Time limit for the whole invocation (global). | | `--only` | Run only tests marked `.only`. | | `--concurrency=N` | Run files or JVM classes in parallel. Default `1`; `0` is invalid. | | `--coverage` | Collect coverage; see [Coverage](#coverage). | | `--reporter=junit` | Write JUnit XML reports. | | `--reporter=tap` | Write TAP 13 to stdout (and under `--reporter-outfile`). | | `--reporter-outfile=DIR` | Report directory. | | `--debugger[=MODE\|ADDRESS]` | Attach a debugger; see below. | | `--debugger-host=HOST`, `--debugger-port=PORT` | JavaScript debugger address (DAP: 4711; CDP: 1337). | | `--debugger` form | Debugs | | --- | --- | | bare | JVM tests over JDWP on `127.0.0.1:5005`, and JavaScript tests. | | `=5005`, `=host:5005` | JVM tests only (JDWP). | | `=dap`, `=cdp` | JavaScript tests only. | Grammar: [Debugging](https://elide.help/docs/debugging). An unknown option or missing value fails before anything runs ([Build Tasks](https://elide.help/docs/toolchain/build-tasks#options)). ## Limits - No Python test discovery; run unittest or pytest instead ([Python tests](https://elide.help/docs/python-testing)). - JVM tests need a manifest. - Not implemented: `node:test` snapshots, `mock.module`, watch mode, programmatic `run()`, `node:test/reporters`. Supported API: [Node test API](https://elide.help/docs/api-node-test). ## Samples - [TypeScript tests](https://elide.help/docs/code-samples#typescript-tests) - [Kotlin tests](https://elide.help/docs/code-samples#kotlin-tests) - [Filter tests with CEL](https://elide.help/docs/code-samples#filter-tests-with-cel) - [JUnit XML in CI](https://elide.help/docs/code-samples#junit-xml-in-ci) Start from a template: ```bash elide init --template java # Java app with a JUnit test elide init --template ktjvm # Kotlin app with a test ```