feat(garmin): log every wrapper subprocess call as structured JSON

backend/internal/garmin/client_test.go

@@ -2,13 +2,17 @@ package garmin
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	"encoding/json"
 	"io"
+	"log/slog"
 	"os/exec"
 	"strings"
 	"testing"
 	"time"
+
+	"geniusrun/backend/internal/applog"
 )
 
 // wireResponsePayload is what a fake wrapper handler returns for one
@@ -91,7 +95,7 @@ func TestSubprocessClient_RoundTrip_DetectsIDMismatch(t *testing.T) {
 	scanner.Buffer(make([]byte, 0, 64*1024), maxWrapperLineBytes)
 	c := &subprocessClient{started: true, enc: json.NewEncoder(reqW), scanner: scanner}
 
-	_, err := c.roundTrip("authenticate", nil)
+	_, err := c.roundTrip(context.Background(), "authenticate", nil)
 	if err == nil || !strings.Contains(err.Error(), "id mismatch") {
 		t.Fatalf("roundTrip error = %v, want an id mismatch error", err)
 	}
@@ -113,7 +117,7 @@ func TestSubprocessClient_RoundTrip_SubprocessClosedIsError(t *testing.T) {
 	scanner.Buffer(make([]byte, 0, 64*1024), maxWrapperLineBytes)
 	c := &subprocessClient{started: true, enc: json.NewEncoder(reqW), scanner: scanner}
 
-	_, err := c.roundTrip("authenticate", nil)
+	_, err := c.roundTrip(context.Background(), "authenticate", nil)
 	if err == nil || !strings.Contains(err.Error(), "closed") {
 		t.Fatalf("roundTrip error = %v, want a subprocess-closed error", err)
 	}
@@ -124,7 +128,7 @@ func TestSubprocessClient_RoundTrip_WrapperErrorPropagates(t *testing.T) {
 		return fakeError("boom")
 	})
 
-	_, err := c.roundTrip("authenticate", nil)
+	_, err := c.roundTrip(context.Background(), "authenticate", nil)
 	if err == nil || !strings.Contains(err.Error(), "boom") {
 		t.Fatalf("roundTrip error = %v, want it to mention %q", err, "boom")
 	}
@@ -394,3 +398,60 @@ func TestSubprocessClient_GetWorkoutByID_ParsesSegments(t *testing.T) {
 		t.Fatalf("workout = %+v", workout)
 	}
 }
+
+func TestSubprocessClient_RoundTrip_LogsCallWithResultPreview(t *testing.T) {
+	c := newFakeWrapperClient(t, func(cmd string, params json.RawMessage) wireResponsePayload {
+		return fakeResult(authResultWire{Status: "mfa_required", Message: "MFA required."})
+	})
+
+	var buf bytes.Buffer
+	logger := slog.New(slog.NewJSONHandler(&buf, nil))
+	ctx := applog.WithLogger(context.Background(), logger)
+
+	if _, err := c.Authenticate(ctx); err != nil {
+		t.Fatalf("Authenticate: %v", err)
+	}
+
+	var entry map[string]any
+	if err := json.Unmarshal(buf.Bytes(), &entry); err != nil {
+		t.Fatalf("log output is not valid JSON: %v (%q)", err, buf.String())
+	}
+	if entry["msg"] != "garmin wrapper call" {
+		t.Errorf("msg = %v, want \"garmin wrapper call\"", entry["msg"])
+	}
+	if entry["cmd"] != "authenticate" {
+		t.Errorf("cmd = %v, want authenticate", entry["cmd"])
+	}
+	preview, _ := entry["result_preview"].(string)
+	if !strings.Contains(preview, "mfa_required") {
+		t.Errorf("result_preview = %q, want it to contain mfa_required", preview)
+	}
+	if _, hasError := entry["error"]; hasError {
+		t.Errorf("expected no error field on a successful call, got %v", entry["error"])
+	}
+}
+
+func TestSubprocessClient_RoundTrip_LogsErrorAtWarnLevel(t *testing.T) {
+	c := newFakeWrapperClient(t, func(cmd string, params json.RawMessage) wireResponsePayload {
+		return fakeError("boom")
+	})
+
+	var buf bytes.Buffer
+	logger := slog.New(slog.NewJSONHandler(&buf, nil))
+	ctx := applog.WithLogger(context.Background(), logger)
+
+	if _, err := c.Authenticate(ctx); err == nil {
+		t.Fatal("expected Authenticate to return an error")
+	}
+
+	var entry map[string]any
+	if err := json.Unmarshal(buf.Bytes(), &entry); err != nil {
+		t.Fatalf("log output is not valid JSON: %v (%q)", err, buf.String())
+	}
+	if entry["level"] != "WARN" {
+		t.Errorf("level = %v, want WARN for a failed call", entry["level"])
+	}
+	if errMsg, _ := entry["error"].(string); !strings.Contains(errMsg, "boom") {
+		t.Errorf("error field = %q, want it to mention \"boom\"", errMsg)
+	}
+}