modules: Add an unstable-rust module

Like other language specific modules this module is module for holding
rust specific helpers. This commit adds a test() function, which
simplifies using rust's internal unittest mechanism.

Rust tests are generally placed in the same code files as they are
testing, in contrast to languages like C/C++ and python which generally
place the tests in separate translation units. For meson this is
somewhat problematic from a repetition point of view, as the only
changes are generally adding --test, and possibly some dependencies.

The rustmod.test() method provides a mechanism to remove the repatition:
it takes a rust target, copies it, and then addes the `--test` option,
then creates a Test() target with the `rust` protocol. You can pass
additional dependencies via the `dependencies` keyword. This all makes
for a nice, DRY, test definition.

2 files changed, 22 insertions, 0 deletions

diff --git a/test cases/rust/9 unit tests/meson.build b/test cases/rust/9 unit tests/meson.build
index 44fd6b6..b649abb 100644
--- a/test cases/rust/9 unit tests/meson.build
+++ b/test cases/rust/9 unit tests/meson.build
@@ -30,3 +30,14 @@ test(
   protocol : 'rust',
   suite : ['foo'],
 )
+
+exe = executable('rust_exe', ['test2.rs', 'test.rs'])
+
+rust = import('unstable-rust')
+rust.test('rust_test_from_exe', exe, should_fail : true)
+
+lib = static_library('rust_static', ['test.rs'])
+rust.test('rust_test_from_static', lib, args: ['--skip', 'test_add_intentional_fail'])
+
+lib = shared_library('rust_shared', ['test.rs'])
+rust.test('rust_test_from_shared', lib, args: ['--skip', 'test_add_intentional_fail'])
diff --git a/test cases/rust/9 unit tests/test2.rs b/test cases/rust/9 unit tests/test2.rs
new file mode 100644
index 0000000..9623c7c
--- /dev/null
+++ b/test cases/rust/9 unit tests/test2.rs
@@ -0,0 +1,11 @@
+mod test;
+use std::env;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let first = args[1].parse::<i32>().expect("Invliad value for first argument.");
+    let second = args[2].parse::<i32>().expect("Invliad value for second argument.");
+
+    let new = test::add(first, second);
+    println!("New value: {}", new);
+}