Fix tests on Linux, allow to run Linux CI locally using act

Author: grega

.github/workflows/ci.yml

@@ -12,6 +12,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
+      - name: Install shellcheck
+        run: command -v shellcheck || sudo apt-get update -qq && sudo apt-get install -qq -y shellcheck
       - name: Run shellcheck
         run: shellcheck hdi
 

README.md

@@ -101,6 +101,17 @@ shellcheck hdi
 bats test/hdi.bats
 ```
 
+### Running Linux tests locally with Act
+
+This assumes that the host system is macOS.
+
+CI runs tests on both macOS and Ubuntu. To run the Ubuntu job locally using [Act](https://github.com/nektos/act) (requires Docker / Docker Desktop):
+
+```bash
+brew install act
+act -j test --matrix os:ubuntu-latest --container-architecture linux/amd64
+```
+
 ## Demo
 
 The demo GIF is generated with [VHS](https://github.com/charmbracelet/vhs). To regenerate it:

hdi

@@ -384,7 +384,7 @@ draw_picker() {
     all)     printf "  %s[all]%s" "$DIM" "$RESET" ;;
   esac
   printf "\n"
-  (( count++ ))
+  (( count += 1 ))
 
   for idx in "${!DISPLAY_LINES[@]}"; do
     local line="${DISPLAY_LINES[$idx]}"
@@ -403,15 +403,15 @@ draw_picker() {
         else
           printf "  %s  %s%s\n" "$GREEN" "$line" "$RESET"
         fi
-        (( count++ ))
+        (( count += 1 ))
         ;;
       empty)
         if [[ -n "$line" ]]; then
           printf "  %s  %s%s\n" "$DIM" "$line" "$RESET"
         else
           printf "\n"
         fi
-        (( count++ ))
+        (( count += 1 ))
         ;;
     esac
   done
@@ -510,14 +510,14 @@ run_interactive() {
     case "$KEY" in
       up|k)
         if (( cursor > 0 )); then
-          (( cursor-- ))
+          (( cursor -= 1 ))
           selected="${CMD_INDICES[$cursor]}"
         fi
         ;;
 
       down|j)
         if (( cursor < num_cmds - 1 )); then
-          (( cursor++ ))
+          (( cursor += 1 ))
           selected="${CMD_INDICES[$cursor]}"
         fi
         ;;

test/hdi.bats

@@ -633,15 +633,33 @@ setup() {
   # Keys: ↓ c q  (navigate down one, copy, quit)
   local keys=$'\x1b[Bcq'
 
-  # Run interactively in a pseudo-TTY via Python pty module.
-  # (script(1) does not reliably forward stdin to the PTY on Linux.)
-  # The sleep ensures hdi has time to draw the picker and set raw mode
-  # before keystrokes arrive — otherwise Linux buffers them in canonical
-  # mode and they never reach the application.
-  { sleep 0.5; printf '%s' "$keys"; } | python3 -c "
-import pty, os, sys
+  # Run interactively in a pseudo-TTY.
+  # We use pty.fork() rather than pty.spawn() because spawn's _copy loop
+  # crashes on Linux (EIO when slave closes) in older Python versions.
+  python3 -c "
+import pty, os, sys, time, select, errno
+
 os.environ['PATH'] = sys.argv[1] + ':' + os.environ['PATH']
-pty.spawn(sys.argv[2:])" "$fake_bin" "$HDI" "$FIXTURES/node-express" >/dev/null 2>&1 || true
+keys = sys.argv[2].encode()
+
+pid, fd = pty.fork()
+if pid == 0:
+    os.execvp(sys.argv[3], sys.argv[3:])
+else:
+    # Wait for hdi to draw picker and enter raw mode
+    time.sleep(0.5)
+    os.write(fd, keys)
+    # Wait for hdi to process keystrokes and exit
+    time.sleep(0.5)
+    # Drain any remaining output
+    try:
+        while select.select([fd], [], [], 0.5)[0]:
+            if not os.read(fd, 4096):
+                break
+    except OSError:
+        pass
+    os.waitpid(pid, 0)
+" "$fake_bin" "$keys" "$HDI" "$FIXTURES/node-express" >/dev/null 2>&1 || true
 
   # Second command in node-express default mode is "nvm use 20"
   [ -f "$clip_file" ]