test(lib/runcmd): verify that runcmd_prepend_to_path works

3 files changed, 44 insertions, 0 deletions

diff --git a/share/python/lib/runcmd.md b/share/python/lib/runcmd.md
index a9d4ed4..4615f69 100644
--- a/share/python/lib/runcmd.md
+++ b/share/python/lib/runcmd.md
@@ -45,6 +45,27 @@ then exit code is not 0
 and command fails
 ~~~
 
+# Check we can prepend to $PATH
+
+This scenario verifies that we can add a directory to the beginning of
+the PATH environment variable, so that we can have `runcmd` invoke a
+binary from our build tree rather than from system directories. This
+is especially useful for testing new versions of software that's
+already installed on the system.
+
+~~~scenario
+given executable script ls from ls.sh
+when I prepend . to PATH
+when I run ls
+then command is successful
+then stdout contains "custom ls, not system ls"
+~~~
+
+~~~{#ls.sh .file .sh .numberLines}
+#!/bin/sh
+echo "custom ls, not system ls"
+~~~
+
 # Check output has what we want
 
 These scenarios verify that stdout or stderr do have something we want
@@ -165,6 +186,9 @@ author: The Subplot project
 template: python
 bindings:
 - runcmd.yaml
+- runcmd_test.yaml
 functions:
 - runcmd.py
+- runcmd_test.py
+- files.py
 ...
diff --git a/share/python/lib/runcmd_test.py b/share/python/lib/runcmd_test.py
new file mode 100644
index 0000000..6aa435a
--- /dev/null
+++ b/share/python/lib/runcmd_test.py
@@ -0,0 +1,15 @@
+import os
+
+
+def create_script_from_embedded(ctx, filename=None, embedded=None):
+    files_create_from_embedded_with_other_name = globals()[
+        "files_create_from_embedded_with_other_name"
+    ]
+
+    # Create the file.
+    files_create_from_embedded_with_other_name(
+        ctx, filename_on_disk=filename, embedded_filename=embedded
+    )
+
+    # Make the new file executable.
+    os.chmod(filename, 0o755)
diff --git a/share/python/lib/runcmd_test.yaml b/share/python/lib/runcmd_test.yaml
new file mode 100644
index 0000000..8ade220
--- /dev/null
+++ b/share/python/lib/runcmd_test.yaml
@@ -0,0 +1,5 @@
+- given: "executable script {filename} from {embedded}"
+  function: create_script_from_embedded
+
+- when: "I prepend {dirname} to PATH"
+  function: runcmd_prepend_to_path