Merge pull request #19120 from in0rdr/feat/document-stderr-redirect

Document stderr redirection for shell_output tests
2025-01-19 20:50:33 +00:00 · 2025-01-19 20:50:33 +00:00 · 55f399c10d
commit 55f399c10d
parent fd0c8519bb 8fa2119719
1 changed files with 8 additions and 0 deletions
--- a/docs/Formula-Cookbook.md
+++ b/docs/Formula-Cookbook.md
@ -334,6 +334,14 @@ test do
 end
 ```

+* If the binary only writes to `stderr`, you can redirect `stderr` to `stdout` for assertions with `shell_output`. For example:
+
+```ruby
+test do
+  assert_match "Output on stderr", shell_output("#{bin}/formula-program 2>&1", 2)
+end
+```
+
 ### Manuals

 Homebrew expects to find manual pages in `#{prefix}/share/man/...`, and not in `#{prefix}/man/...`.