Auto merge of #10706 - merelymyself:master, r=epage

Guide new users to add use `super::*;` to `mod test`

### What does this PR try to resolve?

Currently, `cargo init --lib` produces examples for unit tests. However, new users will find that they are unable to use functions they defined above. This should resolve the confusion.

Fixes #10559

### How should we test and review this PR?

This PR does not create new features. Test this PR using the already-existing tests.

### Additional information

I didn't think this was a major change, so I did not open a RFC for it. Please let me know if I should have!

Author: bors

src/cargo/ops/cargo_new.rs

@@ -809,11 +809,17 @@ fn main() {
 "
         } else {
             b"\
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/auto_git/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/formats_source/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+  left + right
+}
+
 #[cfg(test)]
 mod tests {
+  use super::*;
+
   #[test]
   fn it_works() {
-    let result = 2 + 2;
+    let result = add(2, 2);
     assert_eq!(result, 4);
   }
 }

tests/testsuite/init/fossil_autodetect/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/git_autodetect/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/git_ignore_exists_no_conflicting_entries/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/ignores_failure_to_format_source/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/mercurial_autodetect/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/pijul_autodetect/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }

tests/testsuite/init/simple_git/out/src/lib.rs

@@ -1,8 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn it_works() {
-        let result = 2 + 2;
+        let result = add(2, 2);
         assert_eq!(result, 4);
     }
 }