feat(trycmd): test only exit status with TRYCMD=status

crates/trycmd/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "trycmd"
-version = "0.15.8"
+version = "0.15.9"
 description = "Snapshot testing for a herd of CLI tests"
 authors = ["Ed Page <[email protected]>"]
 homepage = "https://github.com/assert-rs/trycmd"

crates/trycmd/src/cases.rs

@@ -230,11 +230,23 @@ fn parse_include(args: impl IntoIterator<Item = std::ffi::OsString>) -> Option<V
 }
 
 fn parse_mode(var: Option<&std::ffi::OsStr>) -> crate::Mode {
-    if var == Some(std::ffi::OsStr::new("overwrite")) {
-        crate::Mode::Overwrite
-    } else if var == Some(std::ffi::OsStr::new("dump")) {
-        crate::Mode::Dump("dump".into())
-    } else {
-        crate::Mode::Fail
+    use crate::Mode;
+    match var {
+        // [`OsStr`] implements [`PartialEq<str>`] so we can compare it with
+        // [`&str`] directly:
+        Some(x) if x == "overwrite" => Mode::Overwrite,
+        Some(x) if x == "dump" => Mode::Dump("dump".into()),
+        Some(x) if x == "status" => Mode::OnlyStatus,
+        None => Mode::Fail,
+        Some(x) => {
+            #[allow(clippy::print_stderr)]
+            if !x.is_empty() {
+                eprintln!(
+                    "Unknown mode: TRYCMD={}, using the default mode",
+                    x.to_string_lossy()
+                );
+            }
+            Mode::Fail
+        }
     }
 }

crates/trycmd/src/lib.rs

@@ -63,6 +63,12 @@
 //! ```
 //! This will overwrite any existing `.stdout` and `.stderr` file in `tests/cmd`
 //!
+//! To check only the exit status of tests (ignoring outputs), you can run:
+//! ```console
+//! $ TRYCMD=status cargo test --test cli_tests
+//! ```
+//! This may be useful if the command outputs are not reproducible.
+//!
 //! To filter the tests to those with `name1`, `name2`, etc in their file names, you can run:
 //! ```console
 //! cargo test --test cli_tests -- cli_tests trycmd=name1 trycmd=name2...

crates/trycmd/src/runner.rs

@@ -218,7 +218,7 @@ impl Case {
                 step.expected_status = Some(crate::schema::CommandStatus::Skipped);
             }
 
-            let step_status = self.run_step(step, cwd.as_deref(), bins, &substitutions);
+            let step_status = self.run_step(step, cwd.as_deref(), mode, bins, &substitutions);
             if fs_context.is_mutable() && step_status.is_err() && *mode == Mode::Fail {
                 prior_step_failed = true;
             }
@@ -261,7 +261,7 @@ impl Case {
                     }
                 }
             }
-            Mode::Fail => {}
+            Mode::Fail | Mode::OnlyStatus => {}
         }
 
         if sequence.fs.sandbox() {
@@ -305,6 +305,7 @@ impl Case {
         &self,
         step: &mut crate::schema::Step,
         cwd: Option<&std::path::Path>,
+        mode: &Mode,
         bins: &crate::BinRegistry,
         substitutions: &snapbox::Redactions,
     ) -> Result<Output, Output> {
@@ -362,7 +363,10 @@ impl Case {
 
         // For Mode::Dump's sake, allow running all
         let output = self.validate_spawn(output, step.expected_status());
-        let output = self.validate_streams(output, step, substitutions);
+        let output = match mode {
+            Mode::OnlyStatus => output,
+            _ => self.validate_streams(output, step, substitutions),
+        };
 
         if output.is_ok() {
             Ok(output)
@@ -991,6 +995,8 @@ impl std::fmt::Display for FileStatus {
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum Mode {
     Fail,
+    /// Only validate the return statuses of the commands
+    OnlyStatus,
     Overwrite,
     Dump(std::path::PathBuf),
 }
@@ -999,6 +1005,7 @@ impl Mode {
     pub(crate) fn initialize(&self) -> Result<(), std::io::Error> {
         match self {
             Self::Fail => {}
+            Self::OnlyStatus => {}
             Self::Overwrite => {}
             Self::Dump(root) => {
                 std::fs::create_dir_all(root)?;
@@ -1029,7 +1036,7 @@ fn fs_context(
                 }
                 Ok(context)
             }
-            Mode::Fail | Mode::Overwrite => {
+            Mode::Fail | Mode::Overwrite | Mode::OnlyStatus => {
                 let mut context = snapbox::dir::DirRoot::mutable_temp()?;
                 if let Some(cwd) = cwd {
                     context = context.with_template(cwd)?;