identified.
Without explicit settings, the tests will be run using rustfmt's default
-configuration. It is possible to run a test using non-default settings by
-including configuration parameters in comments at the top of the file. For
-example: to use 3 spaces per tab, start your test with
+configuration. It is possible to run a test using non-default settings in several
+ways. Firstly, you can include configuration parameters in comments at the top
+of the file. For example: to use 3 spaces per tab, start your test with
`// rustfmt-tab_spaces: 3`. Just remember that the comment is part of the input,
so include in both the source and target files! It is also possible to
explicitly specify the name of the expected output file in the target directory.
-Use `// rustfmt-target: filename.rs` for this. Finally, you can use a custom
+Use `// rustfmt-target: filename.rs` for this. You can also specify a custom
configuration by using the `rustfmt-config` directive. Rustfmt will then use
that toml file located in `./tests/config/` for its configuration. Including
`// rustfmt-config: small_tabs.toml` will run your test with the configuration
-file found at `./tests/config/small_tabs.toml`.
+file found at `./tests/config/small_tabs.toml`. The final option is used when the
+test source file contains no configuration parameter comments. In this case, the
+test harness looks for a configuration file with the same filename as the test
+file in the `./tests/config/` directory, so a test source file named `test-indent.rs`
+would need a configuration file named `test-indent.toml` in that directory. As an
+example, the `issue-1111.rs` test file is configured by the file
+`./tests/config/issue-1111.toml`.
## Hack!
-Here are some [good starting issues](https://github.com/nrc/rustfmt/issues?q=is%3Aopen+is%3Aissue+label%3Aeasy).
+Here are some [good starting issues](https://github.com/rust-lang-nursery/rustfmt/issues?q=is%3Aopen+is%3Aissue+label%3Agood-first-issue).
If you've found areas which need polish and don't have issues, please submit a
PR, don't feel there needs to be an issue.
more width, then call the function again with more space.
Since it is common for callers to bail out when a callee fails, we often use a
-`try_opt!` macro to make this pattern more succinct.
+`?` operator to make this pattern more succinct.
One way we might find out that we don't have enough space is when computing how much
space we have. Something like `available_space = budget - overhead`. Since
widths are unsized integers, this would cause underflow. Therefore we use
-checked subtraction: `available_space = try_opt!(budget.checked_sub(overhead))`.
-`checked_sub` returns an `Option`, and if we would underflow `try_opt!` returns
+checked subtraction: `available_space = budget.checked_sub(overhead)?`.
+`checked_sub` returns an `Option`, and if we would underflow `?` returns
`None`, otherwise we proceed with the computed space.
Much syntax in Rust is lists: lists of arguments, lists of fields, lists of
`create_config!` macro at the end of the file for all the options. The rest of
the file defines a bunch of enums used for options, and the machinery to produce
the config struct and parse a config file, etc. Checking an option is done by
-accessing the correct field on the config struct, e.g., `config.max_width`. Most
+accessing the correct field on the config struct, e.g., `config.max_width()`. Most
functions have a `Config`, or one can be accessed via a visitor or context of
some kind.
projects / rust.git / blobdiff