feat: add JSON output tests and README docs for analyze and status (#556)

* feat: add JSON output tests and README docs for analyze and status

Add 7 BATS tests covering `--json` output for `mo analyze` and `mo status`:
- schema structure
- field types
- pipe auto-detection.

Also document the `--json` flag in a new "Machine-Readable Output" README section, including the auto-detection behavior when piped.

* chore: use waitgroup go in status collector

---------

Co-authored-by: Tw93 <hitw93@gmail.com>

README.md

@@ -210,6 +210,42 @@ Health score is based on CPU, memory, disk, temperature, and I/O load, with colo
 
 Shortcuts: In `mo status`, press `k` to toggle the cat and save the preference, and `q` to quit.
 
+#### Machine-Readable Output
+
+Both `mo analyze` and `mo status` support a `--json` flag for scripting and automation.
+
+`mo status` also auto-detects when its output is piped (not a terminal) and switches to JSON automatically.
+
+```bash
+# Disk analysis as JSON
+$ mo analyze --json ~/Documents
+{
+  "path": "/Users/you/Documents",
+  "entries": [
+    { "name": "Library", "path": "...", "size": 80939438080, "is_dir": true },
+    ...
+  ],
+  "total_size": 168393441280,
+  "total_files": 42187
+}
+
+# System status as JSON
+$ mo status --json
+{
+  "host": "MacBook-Pro",
+  "health_score": 92,
+  "cpu": { "usage": 45.2, "logical_cpu": 8, ... },
+  "memory": { "total": 25769803776, "used": 15049334784, "used_percent": 58.4 },
+  "disks": [ ... ],
+  "uptime": "3d 12h 45m",
+  ...
+}
+
+# Auto-detected JSON when piped
+$ mo status | jq '.health_score'
+92
+```
+
 ### Project Artifact Purge
 
 Clean old build artifacts such as `node_modules`, `target`, `build`, and `dist` to free up disk space.

cmd/status/metrics.go

@@ -255,9 +255,7 @@ func (c *Collector) Collect() (MetricsSnapshot, error) {
 
 	// Helper to launch concurrent collection.
 	collect := func(fn func() error) {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
+		wg.Go(func() {
 			defer func() {
 				if r := recover(); r != nil {
 					errMu.Lock()
@@ -279,7 +277,7 @@ func (c *Collector) Collect() (MetricsSnapshot, error) {
 				}
 				errMu.Unlock()
 			}
-		}()
+		})
 	}
 
 	// Launch independent collection tasks.

tests/cli.bats

@@ -11,6 +11,19 @@ setup_file() {
 	export HOME
 
 	mkdir -p "$HOME"
+
+	# Build Go binaries from current source for JSON tests.
+	# Point GOPATH/GOMODCACHE at the real home so go build doesn't write
+	# module caches into the fake HOME under tests/.
+	if command -v go > /dev/null 2>&1; then
+		ANALYZE_BIN="$(mktemp "${TMPDIR:-/tmp}/analyze-go.XXXXXX")"
+		STATUS_BIN="$(mktemp "${TMPDIR:-/tmp}/status-go.XXXXXX")"
+		GOPATH="${ORIGINAL_HOME}/go" GOMODCACHE="${ORIGINAL_HOME}/go/pkg/mod" \
+			go build -o "$ANALYZE_BIN" "$PROJECT_ROOT/cmd/analyze" 2>/dev/null
+		GOPATH="${ORIGINAL_HOME}/go" GOMODCACHE="${ORIGINAL_HOME}/go/pkg/mod" \
+			go build -o "$STATUS_BIN" "$PROJECT_ROOT/cmd/status" 2>/dev/null
+		export ANALYZE_BIN STATUS_BIN
+	fi
 }
 
 teardown_file() {
@@ -19,6 +32,7 @@ teardown_file() {
 	if [[ -n "${ORIGINAL_HOME:-}" ]]; then
 		export HOME="$ORIGINAL_HOME"
 	fi
+	rm -f "${ANALYZE_BIN:-}" "${STATUS_BIN:-}"
 }
 
 create_fake_utils() {
@@ -278,3 +292,130 @@ EOF
 	run grep "pam_tid.so" "$pam_file"
 	[ "$status" -ne 0 ]
 }
+
+# --- JSON output mode tests ---
+
+@test "mo analyze --json outputs valid JSON with expected fields" {
+	if [[ ! -x "${ANALYZE_BIN:-}" ]]; then
+		skip "analyze binary not available (go not installed?)"
+	fi
+
+	run "$ANALYZE_BIN" --json /tmp
+	[ "$status" -eq 0 ]
+
+	# Validate it is parseable JSON
+	echo "$output" | python3 -c "import sys, json; json.load(sys.stdin)"
+
+	# Check required top-level keys
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+assert 'path' in data, 'missing path'
+assert 'entries' in data, 'missing entries'
+assert 'total_size' in data, 'missing total_size'
+assert 'total_files' in data, 'missing total_files'
+assert isinstance(data['entries'], list), 'entries is not a list'
+"
+}
+
+@test "mo analyze --json entries contain required fields" {
+	if [[ ! -x "${ANALYZE_BIN:-}" ]]; then
+		skip "analyze binary not available (go not installed?)"
+	fi
+
+	run "$ANALYZE_BIN" --json /tmp
+	[ "$status" -eq 0 ]
+
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+for entry in data['entries']:
+    assert 'name' in entry, 'entry missing name'
+    assert 'path' in entry, 'entry missing path'
+    assert 'size' in entry, 'entry missing size'
+    assert 'is_dir' in entry, 'entry missing is_dir'
+"
+}
+
+@test "mo analyze --json path reflects target directory" {
+	if [[ ! -x "${ANALYZE_BIN:-}" ]]; then
+		skip "analyze binary not available (go not installed?)"
+	fi
+
+	run "$ANALYZE_BIN" --json /tmp
+	[ "$status" -eq 0 ]
+
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+assert data['path'] == '/tmp' or data['path'] == '/private/tmp', \
+    f\"unexpected path: {data['path']}\"
+"
+}
+
+@test "mo status --json outputs valid JSON with expected fields" {
+	if [[ ! -x "${STATUS_BIN:-}" ]]; then
+		skip "status binary not available (go not installed?)"
+	fi
+
+	run "$STATUS_BIN" --json
+	[ "$status" -eq 0 ]
+
+	# Validate it is parseable JSON
+	echo "$output" | python3 -c "import sys, json; json.load(sys.stdin)"
+
+	# Check required top-level keys
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+for key in ['cpu', 'memory', 'disks', 'health_score', 'host', 'uptime']:
+    assert key in data, f'missing key: {key}'
+"
+}
+
+@test "mo status --json cpu section has expected structure" {
+	if [[ ! -x "${STATUS_BIN:-}" ]]; then
+		skip "status binary not available (go not installed?)"
+	fi
+
+	run "$STATUS_BIN" --json
+	[ "$status" -eq 0 ]
+
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+cpu = data['cpu']
+assert 'usage' in cpu, 'cpu missing usage'
+assert 'logical_cpu' in cpu, 'cpu missing logical_cpu'
+assert isinstance(cpu['usage'], (int, float)), 'cpu usage is not a number'
+"
+}
+
+@test "mo status --json memory section has expected structure" {
+	if [[ ! -x "${STATUS_BIN:-}" ]]; then
+		skip "status binary not available (go not installed?)"
+	fi
+
+	run "$STATUS_BIN" --json
+	[ "$status" -eq 0 ]
+
+	echo "$output" | python3 -c "
+import sys, json
+data = json.load(sys.stdin)
+mem = data['memory']
+assert 'total' in mem, 'memory missing total'
+assert 'used' in mem, 'memory missing used'
+assert 'used_percent' in mem, 'memory missing used_percent'
+assert mem['total'] > 0, 'memory total should be positive'
+"
+}
+
+@test "mo status --json piped to stdout auto-detects JSON mode" {
+	if [[ ! -x "${STATUS_BIN:-}" ]]; then
+		skip "status binary not available (go not installed?)"
+	fi
+
+	# When piped (not a tty), status should auto-detect and output JSON
+	output=$("$STATUS_BIN" 2>/dev/null)
+	echo "$output" | python3 -c "import sys, json; json.load(sys.stdin)"
+}