feat: add custom 404 page with playful inline artwork and prose

internal/server/server.go

@@ -28,6 +28,15 @@ func ProvideRouter(cfg config.Config, htmlRender render.HTMLRender) *gin.Engine
 	}
 	r := gin.New()
 	r.Use(CORSMiddlewareWithConfig(cfg), RequestContextMiddleware(), audit.ContextMiddleware(), RequestLogger(), gin.Recovery())
+	r.NoRoute(func(c *gin.Context) {
+		if acceptsHTML(c) {
+			c.HTML(http.StatusNotFound, "not_found.gohtml", gin.H{
+				"CurrentPath": c.Request.URL.Path,
+			})
+			return
+		}
+		c.JSON(http.StatusNotFound, ErrorResponse{Error: "Not found"})
+	})
 	r.Static("/static", "./static")
 	r.Static("/dist", "./dist")
 	r.GET("/debug/pprof", gin.WrapH(http.DefaultServeMux))

internal/server/server_test.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"log"
 	"mal/internal/config"
+	"mal/templates"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -182,3 +183,50 @@ func TestRespondErrorIncludesRequestContext(t *testing.T) {
 		t.Fatalf("log line missing request route: %s", logLine)
 	}
 }
+
+func TestProvideRouterRendersNotFoundPageForHTMLRequests(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	renderer, err := templates.ProvideRenderer()
+	if err != nil {
+		t.Fatalf("ProvideRenderer: %v", err)
+	}
+
+	router := ProvideRouter(config.Config{GinMode: gin.TestMode}, renderer)
+	req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, "/missing", nil)
+	req.Header.Set("Accept", "text/html")
+	rec := httptest.NewRecorder()
+
+	router.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNotFound)
+	}
+	for _, want := range []string{"You got a little lost", "This page slipped off the map for a minute", "Head back home"} {
+		if !strings.Contains(rec.Body.String(), want) {
+			t.Fatalf("not found page missing %q in body:\n%s", want, rec.Body.String())
+		}
+	}
+}
+
+func TestProvideRouterReturnsJSONForAPINotFound(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	renderer, err := templates.ProvideRenderer()
+	if err != nil {
+		t.Fatalf("ProvideRenderer: %v", err)
+	}
+
+	router := ProvideRouter(config.Config{GinMode: gin.TestMode}, renderer)
+	req := httptest.NewRequestWithContext(context.Background(), http.MethodGet, "/api/missing", nil)
+	rec := httptest.NewRecorder()
+
+	router.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNotFound)
+	}
+	if got := rec.Body.String(); got != `{"error":"Not found"}` {
+		t.Fatalf("body = %q, want %q", got, `{"error":"Not found"}`)
+	}
+}