//! `dir-test` provides a macro to generate single test cases from files in a
//! directory.
//!
//! ## Usage
//! Add the following dependency to your `Cargo.toml`.
//!
//! ``` toml
//! [dev-dependencies]
//! dir-test = "0.1"
//! ```
//!
//! ### Basic Usage
//! ```rust, no_run
//! use dir_test::{dir_test, Fixture};
//!
//! #[dir_test(
//!     dir: "$CARGO_MANIFEST_DIR/fixtures",
//!     glob: "**/*.txt",
//! )]
//! fn test(fixture: Fixture<&str>) {
//!     // The file content and the absolute path of the file are available as follows.
//!     let content = fixture.content();
//!     let path = fixture.path();
//!
//!     // Write your test code here.
//!     // ...
//! }
//! ```
//!
//! Assuming your crate is as follows, then the above code generates two test
//! cases `foo()` and `fixtures_a_bar()`.
//!
//! ```text
//! my-crate/
//! ├─ fixtures/
//! │  ├─ foo.txt
//! │  ├─ fixtures_a/
//! │  │  ├─ bar.txt
//! ├─ src/
//! │  ├─ ...
//! │  ├─ lib.rs
//! ├─ Cargo.toml
//! ├─ README.md
//! ```
//!
//! 🔽
//!
//! ```rust, no_run
//! #[test]
//! fn foo() {
//!     test(fixture);
//! }
//!
//! #[test]
//! fn fixtures_a_bar() {
//!     test(fixture);
//! }
//! ```
//!
//! **NOTE**: The `dir` argument must be specified in an absolute path because
//! of the limitation of the current procedural macro system. Consider using
//! environment variables, `dir-test` crate resolves environment variables
//! internally.
//!
//! ### Custom Loader
//! You can specify a custom loader function to load the file content from the
//! file path. The loader will be passed `&'static str` file path and can return
//! an arbitrary type.
//! ```rust, no_run
//! use dir_test::{dir_test, Fixture};
//!
//! #[dir_test(
//!     dir: "$CARGO_MANIFEST_DIR/fixtures",
//!     glob: "**/*.txt",
//!     loader: std::fs::read_to_string,
//! )]
//! fn test(fixture: Fixture<std::io::Result<String>>) {
//!     let content = fixture.content().unwrap();
//!
//!     // ...
//! }
//! ```
//!
//! If the loader function is not specified, the default content type is
//! `&'static str`.
//!
//!  ### Custom Test Name
//!  Test names can be customized by specifying the `postfix` argument.
//! `postfix` is appended to the test name.
//!
//! ```rust, no_run
//! use dir_test::{dir_test, Fixture};
//!
//! #[dir_test(
//!     dir: "$CARGO_MANIFEST_DIR/fixtures",
//!     glob: "**/*.txt",
//!     postfix: "custom", // `_custom` is appended to the test name.
//! )]
//! fn test(fixture: Fixture<std::io::Result<String>>) {
//!     // ...
//! }
//! ```
//!
//!  ### Test Attributes
//!  Test attributes can specified by the `dir_test_attr` attribute. The
//! attributes inside `dir_test_atrr` are applied to the all generated test.
//! **NOTE**: The `dir_test_attr` attribute must be specified after the
//! `dir_test`. cases.
//!
//! ```rust, no_run
//! use dir_test::{dir_test, Fixture};
//!
//! #[dir_test(
//!     dir: "$CARGO_MANIFEST_DIR/fixtures",
//!     glob: "**/*.txt",
//! )]
//! #[dir_test_attr(
//!     #[wasm_bindgen_test]
//!     #[cfg(target_family = "wasm")]
//! )]
//! fn wasm_test(fixture: Fixture<std::io::Result<String>>) {
//!     // ...
//! }
//! ```

/// A fixture contains a file content and its absolute path.
/// Content type is determined by the loader function specified in
/// `dir_test` macro. If the loader is not specified, the default
/// content type is `&'static str`.
pub struct Fixture<T> {
    content: T,
    path: &'static str,
}

impl<T> Fixture<T> {
    #[doc(hidden)]
    /// Creates a new fixture from the given content and path.
    pub fn new(content: T, path: &'static str) -> Self {
        Self { content, path }
    }

    /// Returns the content of the fixture.
    pub fn content(&self) -> &T {
        &self.content
    }

    /// Returns the absolute path of the fixture.
    pub const fn path(&self) -> &'static str {
        self.path
    }
}

/// A procedural macro to generate test cases from files in a directory.
pub use dir_test_macros::dir_test;