[tests] Refine the test naming and error messages

- Make the naming of test cases less ambiguous, e.g., rename
  "missing_input_file" to "missing_input_arg" or "input_file_not_found"
- Unify the error messages on input/output options

tests/cache_check.rs

@@ -40,16 +40,16 @@ fn accepts_help() -> Result<()> {
 }
 
 #[test]
-fn missing_metadata() -> Result<()> {
+fn missing_input_arg() -> Result<()> {
     let stderr = run_fail(cache_check!())?;
     assert!(stderr.contains(msg::MISSING_INPUT_ARG));
     Ok(())
 }
 
 #[test]
-fn no_such_metadata() -> Result<()> {
+fn input_file_not_found() -> Result<()> {
     let stderr = run_fail(cache_check!("/arbitrary/filename"))?;
-    assert!(stderr.contains("No such file or directory"));
+    assert!(stderr.contains(msg::FILE_NOT_FOUND));
     Ok(())
 }
 

tests/common/mod.rs

@@ -20,7 +20,7 @@ use test_dir::TestDir;
 
 #[cfg(not(feature = "rust_tests"))]
 pub mod msg {
-    pub const FILE_NOT_FOUND: &str = "Couldn't stat file";
+    pub const FILE_NOT_FOUND: &str = "No such file or directory";
     pub const MISSING_INPUT_ARG: &str = "No input file provided";
     pub const MISSING_OUTPUT_ARG: &str = "No output file provided";
 }

tests/thin_repair.rs

@@ -48,13 +48,13 @@ fn dont_repair_xml() -> Result<()> {
 }
 
 #[test]
-fn missing_input_file() -> Result<()> {
+fn input_file_not_found() -> Result<()> {
     let mut td = TestDir::new()?;
     let md = mk_zeroed_md(&mut td)?;
     let stderr = run_fail(thin_repair!("-i", "no-such-file", "-o", &md))?;
     assert!(superblock_all_zeroes(&md)?);
     // TODO: replace with msg::FILE_NOT_FOUND once the rust version is ready
-    assert!(stderr.contains("Couldn't stat file"));
+    assert!(stderr.contains("No such file or directory"));
     Ok(())
 }
 
@@ -69,7 +69,7 @@ fn garbage_input_file() -> Result<()> {
 }
 
 #[test]
-fn missing_output_file() -> Result<()> {
+fn missing_output_arg() -> Result<()> {
     let mut td = TestDir::new()?;
     let md = mk_valid_md(&mut td)?;
     let stderr = run_fail(thin_repair!("-i", &md))?;

tests/thin_restore.rs

@@ -40,7 +40,7 @@ fn accepts_help() -> Result<()> {
 }
 
 #[test]
-fn no_input_file() -> Result<()> {
+fn missing_input_arg() -> Result<()> {
     let mut td = TestDir::new()?;
     let md = mk_zeroed_md(&mut td)?;
     let stderr = run_fail(thin_restore!("-o", &md))?;
@@ -49,7 +49,7 @@ fn no_input_file() -> Result<()> {
 }
 
 #[test]
-fn missing_input_file() -> Result<()> {
+fn input_file_not_found() -> Result<()> {
     let mut td = TestDir::new()?;
     let md = mk_zeroed_md(&mut td)?;
     let stderr = run_fail(thin_restore!("-i", "no-such-file", "-o", &md))?;
@@ -69,7 +69,7 @@ fn garbage_input_file() -> Result<()> {
 }
 
 #[test]
-fn no_output_file() -> Result<()> {
+fn missing_output_arg() -> Result<()> {
     let mut td = TestDir::new()?;
     let xml = mk_valid_xml(&mut td)?;
     let stderr = run_fail(thin_restore!("-i", &xml))?;