Future self, please forgive me and don't hit me with the baseball bat again!

http_handlers/errors/notfound_test.go

@@ -0,0 +1,27 @@
+package errors
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/labstack/echo/v4"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewNotFoundError(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest(http.MethodGet, "/notfound", nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+
+	err := NewNotFoundError(c)
+	assert.NoError(t, err)
+	assert.Equal(t, http.StatusNotFound, rec.Code)
+
+	var resp map[string]string
+	e2 := json.Unmarshal(rec.Body.Bytes(), &resp)
+	assert.NoError(t, e2)
+	assert.Equal(t, "Not Found", resp["error"])
+}