add support for formatting files in subdirectories of tests

tests/nested-test-files/empty-tests-dir/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "empty-tests-dir"
+version = "0.1.0"
+authors = ["rustfmt devs <[email protected]>"]
+
+[dependencies]

tests/nested-test-files/empty-tests-dir/src/lib.rs

@@ -0,0 +1 @@
+fn foo() {}

tests/nested-test-files/no-tests-dir/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "no-tests"
+version = "0.1.0"
+authors = ["rustfmt devs <[email protected]>"]
+
+[dependencies]

tests/nested-test-files/no-tests-dir/src/lib.rs

@@ -0,0 +1 @@
+fn foo() {}

tests/nested-test-files/only-root-level-tests-dir/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "foo"
+version = "0.1.0"
+authors = ["rustfmt devs <[email protected]>"]
+
+[dependencies]

tests/nested-test-files/only-root-level-tests-dir/src/lib.rs

@@ -0,0 +1 @@
+fn foo() {}

tests/nested-test-files/only-root-level-tests-dir/tests/bar.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test2() {
+    assert!(true);
+}

tests/nested-test-files/only-root-level-tests-dir/tests/foo.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test1() {
+    assert_eq!(1, 1);
+}

tests/nested-test-files/root-and-nested-tests/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "root-and-nested-tests"
+version = "0.1.0"
+authors = ["rustfmt devs <[email protected]>"]
+edition = "2018"
+
+[dependencies]

tests/nested-test-files/root-and-nested-tests/src/lib.rs

@@ -0,0 +1 @@
+fn foo() {}

tests/nested-test-files/root-and-nested-tests/tests/bar.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test2() {
+    assert!(true);
+}

tests/nested-test-files/root-and-nested-tests/tests/foo.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test1() {
+    assert_eq!(1, 1);
+}

tests/nested-test-files/root-and-nested-tests/tests/nested/deeply-nested/baz.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test_truth() {
+    assert_eq!!(true, true);
+}

tests/nested-test-files/root-and-nested-tests/tests/nested/foo_bar.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test_false() {
+    assert_ne!(false, true);
+}

tests/nested-test-files/root-and-nested-tests/tests/nested/other.rs

@@ -0,0 +1,4 @@
+#[test]
+fn test_add() {
+    assert_eq!(9, 4 + 5);
+}