1# Tint end-to-end tests 2 3This repo contains a large number of end-to-end tests at `<tint>/test`. 4 5## Test files 6 7Test input files have either the `.wgsl`, `.spv` or `.spvasm` file extension. 8 9Each 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. 10 11Each 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`. 12 13An expectation file contains the expected output of Tint, when passed the input file for the given backend. 14 15If 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. 16 17## Running 18 19To 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. 20 21You can pass `--help` to see the full list of command line flags.\ 22The most commonly used flags are: 23 24| flag | description | 25|----------------------|-------------| 26|`--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. 27|`--format` | Filters the tests to the particular backend.<br>Example: `--format hlsl` will just test the HLSL backend. 28|`--generate-expected` | Generate expectation files for the tests that previously had no expectation file, or were marked as `SKIP` but now pass. 29|`--generate-skip` | Generate `SKIP` expectation files for tests that are not currently passing. 30 31## Authoring guidelines 32 33Each test should be as small as possible, and focused on the particular feature being tested. 34 35Use 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. 36