fix: have api-diff.test.sh test api-diff.sh and add dry-run mode

Author: rpocklin

scripts/api-diff/api-diff.sh

@@ -16,19 +16,22 @@ BASE_BRANCH="${BASE_BRANCH:-origin/master}"
 
 FAIL_ON_BREAKING=false
 TARGET_FILE=""
+DRY_RUN=false
 
 # Parse arguments
 for arg in "$@"; do
     if [ "$arg" = "--fail-on-breaking" ]; then
         FAIL_ON_BREAKING=true
+    elif [ "$arg" = "--dry-run" ]; then
+        DRY_RUN=true
     elif [[ "$arg" == *.yaml ]]; then
         TARGET_FILE="$arg"
     fi
 done
 
 # If --fail-on-breaking not explicitly set, determine based on branch name
 if [ "$FAIL_ON_BREAKING" = false ]; then
-    CURRENT_BRANCH=$(git branch --show-current 2>/dev/null || echo "")
+    CURRENT_BRANCH=${CURRENT_BRANCH:-$(git branch --show-current 2>/dev/null || echo "")}
     if [[ "$CURRENT_BRANCH" == *breaking* ]]; then
         echo "Branch '$CURRENT_BRANCH' contains 'breaking', allowing breaking changes"
         FAIL_ON_BREAKING=false
@@ -38,6 +41,16 @@ if [ "$FAIL_ON_BREAKING" = false ]; then
     fi
 fi
 
+if [ "$DRY_RUN" = true ]; then
+    if [ "$FAIL_ON_BREAKING" = true ]; then
+        echo "Mode: Failing on breaking changes"
+    else
+        echo "Mode: Allowing breaking changes"
+    fi
+    echo "Dry run mode, exiting after branch check"
+    exit 0
+fi
+
 echo "Starting API diff check..."
 
 # Ensure we're in the repo root

scripts/api-diff/api-diff.test.sh

@@ -1,61 +1,85 @@
 #!/bin/bash
 
-# Unit test for GitHub Actions branch logic
-# This tests the conditional logic used in .github/workflows/api-diff.yml
+# Unit test for api-diff.sh branch logic
+# Tests the script's branch detection and FAIL_ON_BREAKING setting
 
 set -e
 
-echo "=== Unit Test: Branch Logic Pattern Matching ==="
+echo "=== Unit Test: api-diff.sh Branch Logic ==="
 echo
 
 TESTS_PASSED=0
 TESTS_FAILED=0
 
-# Helper function to test pattern
+SCRIPT_PATH="scripts/api-diff/api-diff.sh"
+
+# Helper function to test script with branch
 test_branch() {
     local branch_name="$1"
-    local should_allow_breaking="$2"
-    local test_ref="refs/heads/$branch_name"
+    local expected_mode="$2"  # "allow" or "fail"
+    local test_name="$3"
 
-    echo "Testing: $branch_name"
+    echo "Testing: $test_name (branch: $branch_name)"
 
-    if [[ "$test_ref" == *breaking* ]]; then
-        local result="allow"
-    else
-        local result="fail"
-    fi
+    # Run the script in dry-run mode with CURRENT_BRANCH set
+    local output
+    output=$(CURRENT_BRANCH="$branch_name" "$SCRIPT_PATH" --dry-run 2>&1)
 
-    if [[ "$result" == "$should_allow_breaking" ]]; then
-        echo "  ✓ PASS: Expected '$should_allow_breaking', got '$result'"
-        TESTS_PASSED=$((TESTS_PASSED + 1))
-    else
-        echo "  ✗ FAIL: Expected '$should_allow_breaking', got '$result'"
-        TESTS_FAILED=$((TESTS_FAILED + 1))
+    # Check the output for the expected message
+    if [[ "$expected_mode" == "allow" ]]; then
+        if echo "$output" | grep -q "Mode: Allowing breaking changes"; then
+            echo "  ✓ PASS: Correctly allows breaking changes"
+            TESTS_PASSED=$((TESTS_PASSED + 1))
+        else
+            echo "  ✗ FAIL: Expected to allow breaking changes, but output was:"
+            echo "$output"
+            TESTS_FAILED=$((TESTS_FAILED + 1))
+        fi
+    elif [[ "$expected_mode" == "fail" ]]; then
+        if echo "$output" | grep -q "Mode: Failing on breaking changes"; then
+            echo "  ✓ PASS: Correctly fails on breaking changes"
+            TESTS_PASSED=$((TESTS_PASSED + 1))
+        else
+            echo "  ✗ FAIL: Expected to fail on breaking changes, but output was:"
+            echo "$output"
+            TESTS_FAILED=$((TESTS_FAILED + 1))
+        fi
     fi
     echo
 }
 
-# Test cases: test_branch "branch-name" "expected-result"
-# expected-result: "allow" = allow breaking changes, "fail" = fail on breaking
+# Test cases: test_branch "branch-name" "expected-mode" "description"
+# expected-mode: "allow" = allows breaking changes, "fail" = fails on breaking
 
 echo "--- Branches that SHOULD allow breaking changes ---"
-test_branch "breaking-api-changes" "allow"
-test_branch "breaking-remove-deprecated" "allow"
-test_branch "breaking-v2" "allow"
-test_branch "breaking-123" "allow"
-test_branch "feature-breaking-change" "allow"  # 'breaking' anywhere in name
-test_branch "fix-breaking-bug" "allow"          # 'breaking' anywhere in name
-test_branch "api-breaking-changes" "allow"      # 'breaking' in middle
-test_branch "update-breaking-endpoint" "allow"  # 'breaking' in middle
+test_branch "breaking-api-changes" "allow" "Branch with 'breaking' at start"
+test_branch "feature-breaking-change" "allow" "Branch with 'breaking' in middle"
+test_branch "fix-breaking-bug" "allow" "Branch with 'breaking' in middle"
+test_branch "api-breaking-changes" "allow" "Branch with 'breaking' in middle"
+test_branch "update-breaking-endpoint" "allow" "Branch with 'breaking' in middle"
 
 echo "--- Branches that SHOULD fail on breaking changes ---"
-test_branch "feature-new-endpoint" "fail"
-test_branch "main" "fail"
-test_branch "master" "fail"
-test_branch "develop" "fail"
-test_branch "add-openapi-diff-tool" "fail"
-test_branch "fix-api-bug" "fail"
-test_branch "feature-v2" "fail"
+test_branch "feature-new-endpoint" "fail" "Normal feature branch"
+test_branch "main" "fail" "Main branch"
+test_branch "master" "fail" "Master branch"
+test_branch "develop" "fail" "Develop branch"
+test_branch "add-openapi-diff-tool" "fail" "Current branch name"
+test_branch "fix-api-bug" "fail" "Bug fix branch"
+test_branch "feature-v2" "fail" "Version feature branch"
+
+echo "--- Test override with --fail-on-breaking ---"
+# Test that --fail-on-breaking overrides branch logic
+echo "Testing override: breaking branch with --fail-on-breaking"
+output=$(CURRENT_BRANCH="breaking-test" "$SCRIPT_PATH" --dry-run --fail-on-breaking 2>&1)
+if echo "$output" | grep -q "Mode: Failing on breaking changes"; then
+    echo "  ✓ PASS: --fail-on-breaking overrides branch logic"
+    TESTS_PASSED=$((TESTS_PASSED + 1))
+else
+    echo "  ✗ FAIL: --fail-on-breaking did not override, output:"
+    echo "$output"
+    TESTS_FAILED=$((TESTS_FAILED + 1))
+fi
+echo
 
 echo "========================================"
 echo "Test Results:"