-
Notifications
You must be signed in to change notification settings - Fork 37
/
lib.rs
91 lines (75 loc) · 2.74 KB
/
lib.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
extern crate proc_macro;
use proc_macro::TokenStream;
use proc_macro2::Span as Span2;
use syn::{parse_macro_input, ItemFn};
use quote::quote;
use syn::parse_quote;
use syn::spanned::Spanned;
use test_case_core::TestCase;
/// Generates tests for given set of data
///
/// In general, test case consists of four elements:
///
/// 1. _(Required)_ Arguments passed to test body
/// 2. _(Optional)_ Expected result
/// 3. _(Optional)_ Test case description
/// 4. _(Required)_ Test body
///
/// When _expected result_ is provided, it is compared against the actual value generated with _test body_ using `assert_eq!`.
/// _Test cases_ that don't provide _expected result_ should contain custom assertions within _test body_ or return `Result` similar to `#[test]` macro.
#[proc_macro_attribute]
#[proc_macro_error::proc_macro_error]
pub fn test_case(args: TokenStream, input: TokenStream) -> TokenStream {
let test_case = parse_macro_input!(args as TestCase);
let mut item = parse_macro_input!(input as ItemFn);
let mut test_cases = vec![(test_case, Span2::call_site())];
let mut attrs_to_remove = vec![];
let legal_test_case_names = [
parse_quote!(test_case),
parse_quote!(test_case::test_case),
parse_quote!(test_case::case),
parse_quote!(case),
];
for (idx, attr) in item.attrs.iter().enumerate() {
if legal_test_case_names.contains(&attr.path) {
let test_case = match attr.parse_args::<TestCase>() {
Ok(test_case) => test_case,
Err(err) => {
return syn::Error::new(
attr.span(),
format!("cannot parse test_case arguments: {err}"),
)
.to_compile_error()
.into()
}
};
test_cases.push((test_case, attr.span()));
attrs_to_remove.push(idx);
}
}
for i in attrs_to_remove.into_iter().rev() {
item.attrs.swap_remove(i);
}
render_test_cases(&test_cases, item)
}
#[allow(unused_mut)]
fn render_test_cases(test_cases: &[(TestCase, Span2)], mut item: ItemFn) -> TokenStream {
let mut rendered_test_cases = vec![];
for (test_case, span) in test_cases {
rendered_test_cases.push(test_case.render(item.clone(), *span));
}
let mod_name = item.sig.ident.clone();
// We don't want any external crate to alter main fn code, we are passing attributes to each sub-function anyway
item.attrs.clear();
let output = quote! {
#[allow(unused_attributes)]
#item
#[cfg(test)]
mod #mod_name {
#[allow(unused_imports)]
use super::*;
#(#rendered_test_cases)*
}
};
output.into()
}