test: add bash 3.2 CI matrix for awk fallback coverage

- Install bash 3.2 from source in the Docker test image
- Add CI matrix that runs the full test suite under both bash 5 and
  bash 3.2 (via TEST_BASH env var passed to save/restore recipes)
- Split benchmarks into a separate job (only needs to run once)
- Fix --model regex capture group for bash 3.2 compat (store pattern
  in a variable — inline capture groups are a syntax error on 3.2)

The bash 3.2 run exercises the awk fallback path in the state cache
(no associative arrays), catching the field-offset regression from
PR #14 where session_id/model/env were shifted by one field.

Author: timvw

.github/workflows/test.yml

@@ -13,6 +13,11 @@ permissions:
 jobs:
   test:
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        bash: [bash, bash3.2]
+    name: test (bash ${{ matrix.bash == 'bash' && '5' || '3.2' }})
     steps:
       - uses: actions/checkout@v4
         with:
@@ -24,14 +29,28 @@ jobs:
       - name: Run tests
         run: |
           mkdir -p test-results
-          docker run --rm -v ${{ github.workspace }}/test-results:/tmp/test-results tmux-assistant-resurrect-test
+          docker run --rm \
+            -e TEST_BASH=${{ matrix.bash }} \
+            -v ${{ github.workspace }}/test-results:/tmp/test-results \
+            tmux-assistant-resurrect-test
 
       - name: Publish test results
         uses: EnricoMi/publish-unit-test-result-action@v2
         if: always()
         with:
           files: test-results/junit.xml
           comment_mode: off
+          check_name: tests (${{ matrix.bash == 'bash' && 'bash 5' || 'bash 3.2' }})
+
+  benchmark:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Build test image
+        run: docker build -t tmux-assistant-resurrect-test -f test/Dockerfile .
 
       - name: Prepare benchmark baseline
         run: |

justfile

@@ -370,12 +370,13 @@ status:
     fi
 
 # Manually trigger a save of current assistant sessions
+# TEST_BASH overrides the interpreter (e.g. bash3.2 for compat testing).
 save:
-    @bash "{{repo_dir}}/scripts/save-assistant-sessions.sh"
+    @"${TEST_BASH:-bash}" "{{repo_dir}}/scripts/save-assistant-sessions.sh"
 
 # Manually trigger a restore of saved assistant sessions
 restore:
-    @bash "{{repo_dir}}/scripts/restore-assistant-sessions.sh"
+    @"${TEST_BASH:-bash}" "{{repo_dir}}/scripts/restore-assistant-sessions.sh"
 
 # Clean up stale state files (from dead processes)
 clean:

scripts/save-assistant-sessions.sh

@@ -391,7 +391,9 @@ resolve_pane_candidates() {
 				fi
 
 				# Fallback: parse --model from CLI args if not in state file.
-				if [ -z "$model" ] && [[ "$cand_args" =~ --model[=\ ]([^\ ]+) ]]; then
+				# Regex stored in variable for bash 3.2 compat (inline capture groups fail).
+				local _model_re='--model[= ]([^ ]+)'
+				if [ -z "$model" ] && [[ "$cand_args" =~ $_model_re ]]; then
 					model="${BASH_REMATCH[1]}"
 				fi
 

test/Dockerfile

@@ -2,7 +2,7 @@ FROM ubuntu:24.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Core tools
+# Core tools + build deps for bash 3.2
 RUN apt-get update && apt-get install -y \
     tmux \
     jq \
@@ -13,8 +13,20 @@ RUN apt-get update && apt-get install -y \
     nodejs \
     npm \
     python3 \
+    gcc \
+    make \
     && rm -rf /var/lib/apt/lists/*
 
+# Install bash 3.2 from source (macOS ships bash 3.2; needed for awk-fallback tests)
+RUN ARCH=$(uname -m) && \
+    case "$ARCH" in x86_64) TRIPLE="x86_64-pc-linux-gnu";; aarch64) TRIPLE="aarch64-unknown-linux-gnu";; *) TRIPLE="$ARCH-pc-linux-gnu";; esac && \
+    curl -sSfL https://ftp.gnu.org/gnu/bash/bash-3.2.tar.gz | tar xz -C /tmp \
+    && cd /tmp/bash-3.2 \
+    && ./configure --build="$TRIPLE" --prefix=/usr/local --without-bash-malloc >/dev/null 2>&1 \
+    && make -j"$(nproc)" >/dev/null 2>&1 \
+    && cp bash /usr/local/bin/bash3.2 \
+    && rm -rf /tmp/bash-3.2
+
 # Install just
 RUN curl -sSf https://just.systems/install.sh | bash -s -- --to /usr/local/bin
 
@@ -34,4 +46,8 @@ WORKDIR /home/testuser
 # Copy the repo in (done as testuser for correct ownership)
 COPY --chown=testuser:testuser . /home/testuser/tmux-assistant-resurrect
 
-ENTRYPOINT ["bash", "/home/testuser/tmux-assistant-resurrect/test/run-tests.sh"]
+# TEST_BASH: override bash used by scripts under test (save/restore).
+# "bash" (default) = system bash 5; "bash3.2" = bash 3.2 awk-fallback path.
+# The test harness itself always runs under bash 5 (explicit in ENTRYPOINT).
+ENV TEST_BASH="bash"
+ENTRYPOINT ["/bin/bash", "/home/testuser/tmux-assistant-resurrect/test/run-tests.sh"]

test/run-tests.sh

@@ -5,6 +5,9 @@ set -euo pipefail
 
 REPO_DIR="$HOME/tmux-assistant-resurrect"
 JUNIT_FILE="${JUNIT_FILE:-/tmp/test-results/junit.xml}"
+echo "Test harness bash: $BASH_VERSION"
+echo "Scripts under test: $(${TEST_BASH:-bash} --version | head -1)"
+echo ""
 PASS=0
 FAIL=0
 ERRORS=""