# Tint end-to-end tests This repo contains a large number of end-to-end tests at `<tint>/test`. ## Test files Test input files have either the `.wgsl`, `.spv` or `.spvasm` file extension. Each test input file is tested against each of the Tint backends. There are `<number-of-input-files>` × `<number-of-tint-backends>` tests that are performed on an unfiltered end-to-end test run. Each backend test can have an **expectation file**. This expectation file sits next to the input file, with a `<input-file>.expected.<format>` extension. For example the test `test/foo.wgsl` would have the HLSL expectation file `test/foo.wgsl.expected.hlsl`. An expectation file contains the expected output of Tint, when passed the input file for the given backend. If the first line of the expectation file starts `SKIP`, then the test will be skipped instead of failing the end-to-end test run. It is good practice to include after the `SKIP` a reason for why the test is being skipped, along with any additional details, such as compiler error messages. ## Running To run the end-to-end tests use the `<tint>/test/test-all.sh` script, passing the path to the tint executable as the first command line argument. You can pass `--help` to see the full list of command line flags.\ The most commonly used flags are: | flag | description | |----------------------|-------------| |`--filter` | Filters the testing to subset of the tests. The filter argument is a glob pattern that can include `*` for any substring of a file or directory, and `**` for any number of directories.<br>Example: `--filter 'expressions/**/i32.wgsl'` will test all the `i32.wgsl` expression tests. |`--format` | Filters the tests to the particular backend.<br>Example: `--format hlsl` will just test the HLSL backend. |`--generate-expected` | Generate expectation files for the tests that previously had no expectation file, or were marked as `SKIP` but now pass. |`--generate-skip` | Generate `SKIP` expectation files for tests that are not currently passing. ## Authoring guidelines Each test should be as small as possible, and focused on the particular feature being tested. Use sub-directories whenever possible to group similar tests, and try to keep the pattern of directories as consistent as possible between different tests. This helps filter tests using the `--filter` glob patterns.