Read these docs front to back, or jump in. Each guide is short. The grammar is small. Most teams ship their first cross-runtime test in under an hour.
# Same file. Every language. test: "Adds two numbers" when: call: "add(a, b)" matrix: - a: 2, b: 3, expect: 5 - a: 7, b: 4, expect: 11 then: return: expect
The docs are split into three short groups. Each entry takes about five minutes to read.
# 1. Install for any host runtime $ pip install testml # 2. Write a single .tml file $ echo "test: hello" > hello.tml # 3. Run it. Same file in every language. $ testml run hello.tml
No demo project to clone. No proprietary runtime. The same three commands work on a fresh laptop or a CI agent.
If you know these, you can read any test file in the repo and predict what it does.
A test file pairs a setup block with one or more assertion blocks. The syntax stays the same in every runtime.
Read the spec →Each bridge maps TestML primitives onto a host runtime. Pick the bridge for your language. The test file never changes.
See bridges →Tables of inputs and expected outputs feed the same assertions. One block can drive hundreds of cases.
View examples →Match by value, regex, JSON shape, or numeric range. Assertions read like documentation and run like code.
Assertion grammar →Pull values from the host environment with $ENV. Share fixtures across runtimes without rewriting them.
Fixture rules →Run TestML inside your pipeline. Exit codes, JUnit XML, and a clean diff format slot into existing CI tools.
Pipeline guide →TestML ships through the package manager your team already uses. Pick the host you build in. The test file stays the same.
There is no paid tier. There is no telemetry. The runtime is open source under the MIT licence.
$ pip install testml $ testml run tests/
$ npm install --save-dev testml $ npx testml run tests/
$ gem install testml $ testml run spec/
Read the steps left to right. The code on the right matches each step in order.
The test key holds a short, plain sentence. Reports and CI output use this name as-is. Write it for the next engineer.
The when block lists what the host runtime does. Call a function. Hit an endpoint. Read a file. One block per case.
The matrix block is a table. Each row becomes a separate run with the same assertions. Edge cases live next to happy paths.
The then block lists assertions. Match a value, a regex, or a JSON shape. Failures point at the row that broke.
The file does not change. Swap the runtime by swapping the bridge. The Python suite and the Java suite stay in sync by default.
# step 01 — name test: "Parser round-trip preserves keys" # step 02 — action when: call: "parse_then_dump(input)" # step 03 — data table matrix: - input: "a: 1" - input: "nested:\n b: 2" # step 04 — assertion then: equals: input
Bookmark this card. Every key, sigil, and matcher you will see in the wild.
NEXT·pick a path
Start with the quickstart for a five-minute green build. Or open the spec and read the grammar end to end. Both paths land in the same place.