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//
//! Some setup and teardown macro helpers to mimic [Jest's setup and teardown](https://jestjs.io/docs/setup-teardown)
//! functionality. Also includes a `skip` macro that mimics the [skip](https://jestjs.io/docs/api#testskipname-fn)
//! functionality in Jest.
//!
//! There are currently five macros provided: `after_all`,
//! `after_each`, `before_all`, `before_each`, and `skip`. I would like to implement `only` to
//! match [Jest's only](https://jestjs.io/docs/api#testonlyname-fn-timeout) functionality. I'm
//! unsure of a great way to do that currently, however.
//!
//! ## Getting Started
//! Using these macros is fairly simple. The four after/before functions all require a function
//! with the same name as the attribute and are only valid when applied to a mod. They are all used
//! like in the below example. Replace `before_each` with whichever method you want to use. The
//! code in the matching function will be inserted into every fn in the containing mod that has an
//! attribute with the word "test" in it. This is to allow for use with not just normal `#[test]`
//! attributes, but also other flavors like `#[tokio::test]` and `#[test_case(0)]`.
//! ```
//! #[cfg(test)]
//! use test_env_helpers::*;
//!
//! #[before_each]
//! #[cfg(test)]
//! mod my_tests{
//! fn before_each(){println!("I'm in every test!")}
//! #[test]
//! fn test_1(){}
//! #[test]
//! fn test_2(){}
//! #[test]
//! fn test_3(){}
//! }
//! ```
//!
//! The `skip` macro is valid on either a mod or an individual test and will remove the mod or test
//! it is applied to. You can use it to skip tests that aren't working correctly or that you don't
//! want to run for some reason.
//!
//! ```
//! #[cfg(test)]
//! use test_env_helpers::*;
//!
//! #[cfg(test)]
//! mod my_tests{
//! #[skip]
//! #[test]
//! fn broken_test(){panic!("I'm hella broke")}
//! #[skip]
//! mod broken_mod{
//! #[test]
//! fn i_will_not_be_run(){panic!("I get skipped too")}
//! }
//! #[test]
//! fn test_2(){}
//! #[test]
//! fn test_3(){}
//! }
//! ```
extern crate proc_macro;
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, parse_quote, Item, Stmt};
/// Will run the code in the matching `after_all` function exactly once when all of the tests have
/// run. This works by counting the number of `#[test]` attributes and decrementing a counter at
/// the beginning of every test. Once the counter reaches 0, it will run the code in `after_all`.
/// It uses [std::sync::Once](https://doc.rust-lang.org/std/sync/struct.Once.html) internally
/// to ensure that the code is run at maximum one time.
///
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[after_all]
/// #[cfg(test)]
/// mod my_tests{
/// fn after_all(){println!("I only get run once at the very end")}
/// #[test]
/// fn test_1(){}
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
#[proc_macro_attribute]
pub fn after_all(_metadata: TokenStream, input: TokenStream) -> TokenStream {
let input: Item = match parse_macro_input!(input as Item) {
Item::Mod(mut m) => {
let (brace, items) = m.content.unwrap();
let (after_all_fn, everything_else): (Vec<Item>, Vec<Item>) =
items.into_iter().partition(|t| match t {
Item::Fn(f) => f.sig.ident == "after_all",
_ => false,
});
let after_all_fn_block = if after_all_fn.len() != 1 {
panic!("The `after_all` macro attribute requires a single function named `after_all` in the body of the module it is called on.")
} else {
match after_all_fn.into_iter().next().unwrap() {
Item::Fn(f) => f.block,
_ => unreachable!(),
}
};
let inc_count: Stmt = parse_quote!(
REMAINING_TESTS.fetch_sub(1, Ordering::SeqCst);
);
let after_all_if: Stmt = parse_quote! {
if REMAINING_TESTS.load(Ordering::SeqCst) <= 0{
AFTER_ALL.call_once(|| {
#after_all_fn_block
});
}
};
let mut count: usize = 0;
let mut e: Vec<Item> = everything_else
.into_iter()
.map(|t| match t {
Item::Fn(mut f) => {
let test_count = f
.attrs
.iter()
.filter(|attr| {
attr.path
.segments
.iter()
.any(|segment| segment.ident.to_string().contains("test"))
})
.count();
if test_count > 0 {
count += test_count;
let mut stmts = vec![inc_count.clone()];
stmts.append(&mut f.block.stmts);
stmts.push(after_all_if.clone());
f.block.stmts = stmts;
Item::Fn(f)
} else {
Item::Fn(f)
}
}
e => e,
})
.collect();
let use_once: Item = parse_quote!(
use std::sync::Once;
);
let static_once: Item = parse_quote!(
static AFTER_ALL: Once = Once::new();
);
let static_count: Item = parse_quote!(
static REMAINING_TESTS: AtomicUsize = AtomicUsize::new(#count);
);
let mut once_content = vec![use_once, static_once, static_count];
once_content.append(&mut e);
m.content = Some((brace, once_content));
Item::Mod(m)
}
_ => {
panic!("The `after_all` macro attribute is only valid when called on a module.")
}
};
TokenStream::from(quote! (#input))
}
/// Will run the code in the matching `after_each` function at the end of every `#[test]` function.
/// Useful if you want to cleanup after a test or reset some external state. If the test panics,
/// this code will not be run. If you need something that is infallible, you should use
/// `before_each` instead.
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[after_each]
/// #[cfg(test)]
/// mod my_tests{
/// fn after_each(){println!("I get run at the very end of each function")}
/// #[test]
/// fn test_1(){}
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
#[proc_macro_attribute]
pub fn after_each(_metadata: TokenStream, input: TokenStream) -> TokenStream {
let input: Item = match parse_macro_input!(input as Item) {
Item::Mod(mut m) => {
let (brace, items) = m.content.unwrap();
let (after_each_fn, everything_else): (Vec<Item>, Vec<Item>) =
items.into_iter().partition(|t| match t {
Item::Fn(f) => f.sig.ident == "after_each",
_ => false,
});
let after_each_fn_block = if after_each_fn.len() != 1 {
panic!("The `after_each` macro attribute requires a single function named `after_each` in the body of the module it is called on.")
} else {
match after_each_fn.into_iter().next().unwrap() {
Item::Fn(f) => f.block,
_ => unreachable!(),
}
};
let e: Vec<Item> = everything_else
.into_iter()
.map(|t| match t {
Item::Fn(mut f) => {
if f.attrs.iter().any(|attr| {
attr.path
.segments
.iter()
.any(|segment| segment.ident.to_string().contains("test"))
}) {
f.block.stmts.append(&mut after_each_fn_block.stmts.clone());
Item::Fn(f)
} else {
Item::Fn(f)
}
}
e => e,
})
.collect();
m.content = Some((brace, e));
Item::Mod(m)
}
_ => {
panic!("The `after_each` macro attribute is only valid when called on a module.")
}
};
TokenStream::from(quote! {#input})
}
/// Will run the code in the matching `before_all` function exactly once at the very beginning of a
/// test run. It uses [std::sync::Once](https://doc.rust-lang.org/std/sync/struct.Once.html) internally
/// to ensure that the code is run at maximum one time. Useful for setting up some external state
/// that will be reused in multiple tests.
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[before_all]
/// #[cfg(test)]
/// mod my_tests{
/// fn before_all(){println!("I get run at the very beginning of the test suite")}
/// #[test]
/// fn test_1(){}
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
#[proc_macro_attribute]
pub fn before_all(_metadata: TokenStream, input: TokenStream) -> TokenStream {
let input: Item = match parse_macro_input!(input as Item) {
Item::Mod(mut m) => {
let (brace, items) = m.content.unwrap();
let (before_all_fn, everything_else): (Vec<Item>, Vec<Item>) =
items.into_iter().partition(|t| match t {
Item::Fn(f) => f.sig.ident == "before_all",
_ => false,
});
let before_all_fn_block = if before_all_fn.len() != 1 {
panic!("The `before_all` macro attribute requires a single function named `before_all` in the body of the module it is called on.")
} else {
match before_all_fn.into_iter().next().unwrap() {
Item::Fn(f) => f.block,
_ => unreachable!(),
}
};
let q: Stmt = parse_quote! {
BEFORE_ALL.call_once(|| {
#before_all_fn_block
});
};
let mut e: Vec<Item> = everything_else
.into_iter()
.map(|t| match t {
Item::Fn(mut f) => {
if f.attrs.iter().any(|attr| {
attr.path
.segments
.iter()
.any(|segment| segment.ident.to_string().contains("test"))
}) {
let mut stmts = vec![q.clone()];
stmts.append(&mut f.block.stmts);
f.block.stmts = stmts;
Item::Fn(f)
} else {
Item::Fn(f)
}
}
e => e,
})
.collect();
let use_once: Item = parse_quote!(
use std::sync::Once;
);
let static_once: Item = parse_quote!(
static BEFORE_ALL: Once = Once::new();
);
let mut once_content = vec![use_once, static_once];
once_content.append(&mut e);
m.content = Some((brace, once_content));
Item::Mod(m)
}
_ => {
panic!("The `before_all` macro attribute is only valid when called on a module.")
}
};
TokenStream::from(quote! (#input))
}
/// Will run the code in the matching `before_each` function at the beginning of every test. Useful
/// to reset state to ensure that a test has a clean slate.
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[before_each]
/// #[cfg(test)]
/// mod my_tests{
/// fn before_each(){println!("I get run at the very beginning of every test")}
/// #[test]
/// fn test_1(){}
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
///
/// Can be used to reduce the amount of boilerplate setup code that needs to be copied into each test.
/// For example, if you need to ensure that tests in a single test suite are not run in parallel, this can
/// easily be done with a [Mutex](https://doc.rust-lang.org/std/sync/struct.Mutex.html).
/// However, remembering to copy and paste the code to acquire a lock on the `Mutex` in every test
/// is tedious and error prone.
/// ```
/// #[cfg(test)]
/// mod without_before_each{
/// lazy_static! {
/// static ref MTX: Mutex<()> = Mutex::new(());
/// }
/// #[test]
/// fn test_1(){let _m = MTX.lock();}
/// #[test]
/// fn test_2(){let _m = MTX.lock();}
/// #[test]
/// fn test_3(){let _m = MTX.lock();}
/// }
/// ```
/// Using `before_each` removes the need to copy and paste so much and makes making changes easier
/// because they only need to be made in a single location instead of once for every test.
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[before_each]
/// #[cfg(test)]
/// mod with_before_each{
/// lazy_static! {
/// static ref MTX: Mutex<()> = Mutex::new(());
/// }
/// fn before_each(){let _m = MTX.lock();}
/// #[test]
/// fn test_1(){}
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
#[proc_macro_attribute]
pub fn before_each(_metadata: TokenStream, input: TokenStream) -> TokenStream {
let input: Item = match parse_macro_input!(input as Item) {
Item::Mod(mut m) => {
let (brace, items) = m.content.unwrap();
let (before_each_fn, everything_else): (Vec<Item>, Vec<Item>) =
items.into_iter().partition(|t| match t {
Item::Fn(f) => f.sig.ident == "before_each",
_ => false,
});
let before_each_fn_block = if before_each_fn.len() != 1 {
panic!("The `before_each` macro attribute requires a single function named `before_each` in the body of the module it is called on.")
} else {
match before_each_fn.into_iter().next().unwrap() {
Item::Fn(f) => f.block,
_ => unreachable!(),
}
};
let e: Vec<Item> = everything_else
.into_iter()
.map(|t| match t {
Item::Fn(mut f) => {
if f.attrs.iter().any(|attr| {
attr.path
.segments
.iter()
.any(|segment| segment.ident.to_string().contains("test"))
}) {
let mut b = before_each_fn_block.stmts.clone();
b.append(&mut f.block.stmts);
f.block.stmts = b;
Item::Fn(f)
} else {
Item::Fn(f)
}
}
e => e,
})
.collect();
m.content = Some((brace, e));
Item::Mod(m)
}
_ => {
panic!("The `before_each` macro attribute is only valid when called on a module.")
}
};
TokenStream::from(quote! {#input})
}
/// Will skip running the code it is applied on. You can use it to skip tests that aren't working
/// correctly or that you don't want to run for some reason. There are no checks to make sure it's
/// applied to a `#[test]` or mod. It will remove whatever it is applied to from the final AST.
///
/// ```
/// #[cfg(test)]
/// use test_env_helpers::*;
///
/// #[cfg(test)]
/// mod my_tests{
/// #[skip]
/// #[test]
/// fn broken_test(){panic!("I'm hella broke")}
/// #[skip]
/// mod broken_mod{
/// #[test]
/// fn i_will_not_be_run(){panic!("I get skipped too")}
/// }
/// #[test]
/// fn test_2(){}
/// #[test]
/// fn test_3(){}
/// }
/// ```
#[proc_macro_attribute]
pub fn skip(_metadata: TokenStream, _input: TokenStream) -> TokenStream {
TokenStream::from(quote! {})
}