Add test when running from non-existent directory

When fd is run from a non-existent directory, but a search path is
passed in the arguments, it should still run. This tests for that.

tests/testenv/mod.rs

@@ -185,6 +185,11 @@ impl TestEnv {
         self.temp_dir.path().to_path_buf()
     }
 
+    /// Get the path of the fd executable.
+    pub fn test_exe(&self) -> &PathBuf {
+        &self.fd_exe
+    }
+
     /// Get the root directory of the file system.
     pub fn system_root(&self) -> PathBuf {
         let mut components = self.temp_dir.path().components();

tests/tests.rs

@@ -2114,3 +2114,25 @@ fn test_strip_cwd_prefix() {
         symlink",
     );
 }
+
+/// When fd is ran from a non-existent working directory, but an existent
+/// directory is passed in the arguments, it should still run fine
+#[test]
+fn test_invalid_cwd() {
+    let te = TestEnv::new(&[], &[]);
+
+    let root = te.test_root().join("foo");
+    fs::create_dir(&root).unwrap();
+    std::env::set_current_dir(&root).unwrap();
+    fs::remove_dir(&root).unwrap();
+
+    let output = std::process::Command::new(&te.test_exe())
+        .arg("query")
+        .arg(te.test_root())
+        .output()
+        .unwrap();
+
+    if !output.status.success() {
+        panic!("{:?}", output);
+    }
+}