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+# Tests
+
+Many of the tests in this repository are based on [pin-project's tests](https://github.com/taiki-e/pin-project/tree/HEAD/tests).
+
+To run all tests, run the following command:
+
+```sh
+cargo +nightly test --all
+```
+
+## UI tests (`ui`, `compiletest.rs`)
+
+This checks errors detected by the macro or the Rust compiler in the resulting
+expanded code.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test compiletest
+```
+
+Locally, this test updates the files in the `ui` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`ui` directory after running the test, please commit them.
+
+See also [`trybuild` documentation](https://docs.rs/trybuild).
+
+## Expansion tests (`expand`, `expandtest.rs`)
+
+Similar to ui tests, but instead of checking the compiler output, this checks
+the code generated by macros.
+
+See pin-project's [examples](https://github.com/taiki-e/pin-project/tree/HEAD/examples)
+for descriptions of what the generated code does, and why it needs to be generated.
+
+To run this test, run the following command:
+
+```sh
+cargo +nightly test --test expandtest
+```
+
+Locally, this test updates the files in the `expand` directory if there are
+changes to the generated code. If there are any changes to the files in the
+`expand` directory after running the test, please commit them.
+
+See also [`macrotest` documentation](https://docs.rs/macrotest).