feat: Use test name for dir when running tests

crates/cargo-test-macro/src/lib.rs

@@ -133,6 +133,9 @@ pub fn cargo_test(attr: TokenStream, item: TokenStream) -> TokenStream {
         add_attr(&mut ret, "ignore", reason);
     }
 
+    let mut test_name = None;
+    let mut num = 0;
+
     // Find where the function body starts, and add the boilerplate at the start.
     for token in item {
         let group = match token {
@@ -144,18 +147,61 @@ pub fn cargo_test(attr: TokenStream, item: TokenStream) -> TokenStream {
                     continue;
                 }
             }
+            TokenTree::Ident(i) => {
+                // The first time through it will be `fn` the second time is the
+                // name of the test.
+                if test_name.is_none() && num == 1 {
+                    test_name = Some(i.to_string())
+                } else {
+                    num += 1;
+                }
+                ret.extend(Some(TokenTree::Ident(i)));
+                continue;
+            }
             other => {
                 ret.extend(Some(other));
                 continue;
             }
         };
 
-        let mut new_body = to_token_stream(
-            r#"let _test_guard = {
+        let name = &test_name
+            .clone()
+            .map(|n| n.split("::").next().unwrap().to_string())
+            .unwrap();
+        let mut new_body = to_token_stream(&format!(
+            r#"let _test_guard = {{
                 let tmp_dir = option_env!("CARGO_TARGET_TMPDIR");
-                cargo_test_support::paths::init_root(tmp_dir)
-            };"#,
-        );
+                // looks at `file!()` to figure out where the test's directory should be.
+                // test fn `workspaces::workspace_in_git`
+                //   -> `file!` expands to `tests/testsuite/workspaces.rs`
+                //   -> `testsuite/workspaces`
+                // test fn `cargo_remove::cargo_remove::invalid_arg::case`
+                //   -> `file!` expands to `tests/testsuite/cargo_remove/invalid_arg.rs`
+                //   -> `testsuite/cargo_remove/invalid_arg`
+                // test fn `build-std::cross_custom`
+                //   -> `file!` expands to `tests/build-std/main.rs`
+                //   -> `build-std/main`
+                let test_dir: std::path::PathBuf = std::path::PathBuf::from(std::file!())
+                    .components()
+                    // skips `tests`
+                    .skip(1)
+                    // gets 0-3 of the nest componests. 3 is needed since we use
+                    // the file name for `snapbox` tests as the test name.
+                    .take(3)
+                    // remove `.rs` when using file name as test name
+                    .map(|c| c.as_os_str().to_str().unwrap().trim_end_matches(".rs"))
+                    .collect();
+                // some `snapbox` tests (i.e. `cargo_remove` ) use `case` as the test name.
+                // In this case we should use the file name as the test name. If it doesn't
+                // `case` add `name` to the `Pathbuf`
+                let test_dir = if "{name}" == "case" {{
+                    test_dir
+                }} else {{
+                    test_dir.join("{name}").to_path_buf()
+                }};
+                cargo_test_support::paths::init_root(tmp_dir, test_dir)
+            }};"#
+        ));
 
         new_body.extend(group.stream());
         ret.extend(Some(TokenTree::from(Group::new(

crates/cargo-test-support/src/paths.rs

@@ -7,7 +7,6 @@ use std::fs;
 use std::io::{self, ErrorKind};
 use std::path::{Path, PathBuf};
 use std::process::Command;
-use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Mutex;
 
 static CARGO_INTEGRATION_TEST_DIR: &str = "cit";
@@ -60,19 +59,15 @@ pub fn global_root() -> PathBuf {
 // [*] It does set the thread name, but only when running concurrently. If not
 // running concurrently, all tests are run on the main thread.
 thread_local! {
-    static TEST_ID: RefCell<Option<usize>> = RefCell::new(None);
+    static TEST_NAME: RefCell<Option<PathBuf>> = RefCell::new(None);
 }
 
 pub struct TestIdGuard {
     _private: (),
 }
 
-pub fn init_root(tmp_dir: Option<&'static str>) -> TestIdGuard {
-    static NEXT_ID: AtomicUsize = AtomicUsize::new(0);
-
-    let id = NEXT_ID.fetch_add(1, Ordering::SeqCst);
-    TEST_ID.with(|n| *n.borrow_mut() = Some(id));
-
+pub fn init_root(tmp_dir: Option<&'static str>, test_name: PathBuf) -> TestIdGuard {
+    TEST_NAME.with(|n| *n.borrow_mut() = Some(test_name));
     let guard = TestIdGuard { _private: () };
 
     set_global_root(tmp_dir);
@@ -85,20 +80,20 @@ pub fn init_root(tmp_dir: Option<&'static str>) -> TestIdGuard {
 
 impl Drop for TestIdGuard {
     fn drop(&mut self) {
-        TEST_ID.with(|n| *n.borrow_mut() = None);
+        TEST_NAME.with(|n| *n.borrow_mut() = None);
     }
 }
 
 pub fn root() -> PathBuf {
-    let id = TEST_ID.with(|n| {
-        n.borrow().expect(
+    let test_name = TEST_NAME.with(|n| {
+        n.borrow().clone().expect(
             "Tests must use the `#[cargo_test]` attribute in \
              order to be able to use the crate root.",
         )
     });
 
     let mut root = global_root();
-    root.push(&format!("t{}", id));
+    root.push(&test_name);
     root
 }
 

src/doc/contrib/src/tests/writing.md

@@ -65,8 +65,9 @@ The [`#[cargo_test]` attribute](#cargo_test-attribute) is used in place of `#[te
 #### `#[cargo_test]` attribute
 
 The `#[cargo_test]` attribute injects code which does some setup before starting the test.
-It will create a filesystem "sandbox" under the "cargo integration test" directory for each test, such as `/path/to/cargo/target/tmp/cit/t123/`.
-The sandbox will contain a `home` directory that will be used instead of your normal home directory.
+It will create a filesystem "sandbox" under the "cargo integration test" directory for each test, such as
+`/path/to/cargo/target/tmp/cit/testsuite/bad_config/bad1`. The sandbox will contain a `home` directory that
+will be used instead of your normal home directory.
 
 The `#[cargo_test]` attribute takes several options that will affect how the test is generated.
 They are listed in parentheses separated with commas, such as:
@@ -200,7 +201,7 @@ Then populate
 - This attribute injects code which does some setup before starting the
   test, creating a filesystem "sandbox" under the "cargo integration test"
   directory for each test such as
-  `/path/to/cargo/target/cit/t123/`
+  `/path/to/cargo/target/tmp/cit/testsuite/cargo_add/add_basic`
 - The sandbox will contain a `home` directory that will be used instead of your normal home directory
 
 `Project`:
@@ -267,9 +268,9 @@ environment. The general process is:
 
    `cargo test --test testsuite -- features2::inactivate_targets`.
 2. In another terminal, head into the sandbox directory to inspect the files and run `cargo` directly.
-    1. The sandbox directories start with `t0` for the first test.
+    1. The sandbox directories match the format of `tests/testsuite`, just replace `tests` with `target/tmp/cit` 
 
-       `cd target/tmp/cit/t0`
+       `cd target/tmp/cit/testsuite/features2/inactivate_target`
     2. Set up the environment so that the sandbox configuration takes effect:
 
        `export CARGO_HOME=$(pwd)/home/.cargo`