ripgrep: use exit code 2 to indicate error

Exit code 1 was shared to indicate both "no results" and "error." Use
status code 2 to indicate errors, similar to grep's behavior.

Fixes #948 

PR #954

src/main.rs

@@ -60,7 +60,7 @@ fn main() {
         Ok(_) => process::exit(0),
         Err(err) => {
             eprintln!("{}", err);
-            process::exit(1);
+            process::exit(2);
         }
     }
 }

tests/tests.rs

@@ -2191,3 +2191,33 @@ fn type_list() {
     // This can change over time, so just make sure we print something.
     assert!(!lines.is_empty());
 }
+
+// See: https://github.com/BurntSushi/ripgrep/issues/948
+sherlock!(
+    exit_code_match_success,
+    ".",
+    ".",
+    |wd: WorkDir, mut cmd: Command| {
+        wd.assert_exit_code(0, &mut cmd);
+    }
+);
+
+// See: https://github.com/BurntSushi/ripgrep/issues/948
+sherlock!(
+    exit_code_no_match,
+    "6d28e48b5224a42b167e{10}",
+    ".",
+    |wd: WorkDir, mut cmd: Command| {
+        wd.assert_exit_code(1, &mut cmd);
+    }
+);
+
+// See: https://github.com/BurntSushi/ripgrep/issues/948
+sherlock!(
+    exit_code_error,
+    "*",
+    ".",
+    |wd: WorkDir, mut cmd: Command| {
+        wd.assert_exit_code(2, &mut cmd);
+    }
+);

tests/workdir.rs

@@ -261,18 +261,37 @@ impl WorkDir {
     pub fn assert_err(&self, cmd: &mut process::Command) {
         let o = cmd.output().unwrap();
         if o.status.success() {
-            panic!("\n\n===== {:?} =====\n\
+            panic!(
+                "\n\n===== {:?} =====\n\
                  command succeeded but expected failure!\
                  \n\ncwd: {}\
                  \n\nstatus: {}\
                  \n\nstdout: {}\n\nstderr: {}\
                  \n\n=====\n",
-                   cmd, self.dir.display(), o.status,
+                cmd,
+                self.dir.display(),
+                o.status,
                 String::from_utf8_lossy(&o.stdout),
-                   String::from_utf8_lossy(&o.stderr));
+                String::from_utf8_lossy(&o.stderr)
+            );
         }
     }
 
+    /// Runs the given command and asserts that its exit code matches expected exit code.
+    pub fn assert_exit_code(&self, expected_code: i32, cmd: &mut process::Command) {
+        let code = cmd.status().unwrap().code().unwrap();
+
+        assert_eq!(
+            expected_code, code,
+            "\n\n===== {:?} =====\n\
+             expected exit code did not match\
+             \n\nexpected: {}\
+             \n\nfound: {}\
+             \n\n=====\n",
+            cmd, expected_code, code
+        );
+    }
+
     /// Runs the given command and asserts that something was printed to
     /// stderr.
     pub fn assert_non_empty_stderr(&self, cmd: &mut process::Command) {