From d9ed72a5afbb85baf7264c6275c0fe34dfe513c3 Mon Sep 17 00:00:00 2001
From: skidoodle <contact@albert.lol>
Date: Tue, 21 Apr 2026 09:31:12 +0200
Subject: [PATCH] throw error on empty save

---
 handler/http.go         | 24 +++++++++++++++++++++---
 handler/http_test.go    |  3 +++
 view/static/style.css   | 12 ++++++++++++
 view/templates/bin.html |  7 ++++++-
 4 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/handler/http.go b/handler/http.go
index fb6b628..3e2b47c 100644
--- a/handler/http.go
+++ b/handler/http.go
@@ -24,6 +24,7 @@ type ViewData struct {
 	TimeAgo    string
 	LineCount  int
 	GutterSize int
+	Error      string
 }
 
 func NewHandler(store store.Store, maxSize int64, tmplPattern string) *HttpHandler {
@@ -43,17 +44,34 @@ func NewHandler(store store.Store, maxSize int64, tmplPattern string) *HttpHandl
 func (h *HttpHandler) HandleSet(w http.ResponseWriter, r *http.Request) {
 	r.Body = http.MaxBytesReader(w, r.Body, h.maxSize)
 	if err := r.ParseForm(); err != nil {
+		data := ViewData{
+			Title:     "pastebin",
+			IsPreview: false,
+			Content:   r.FormValue("content"),
+		}
 		if strings.Contains(err.Error(), "request body too large") {
-			badRequest("content too large", err, w, r)
+			data.Error = "Content too large"
 		} else {
-			badRequest("invalid form data", err, w, r)
+			data.Error = "Invalid form data"
+		}
+		w.WriteHeader(http.StatusBadRequest)
+		if err := h.templates.ExecuteTemplate(w, "base", data); err != nil {
+			internal("could not render template", err, w, r)
 		}
 		return
 	}
 
 	content := r.FormValue("content")
 	if content == "" {
-		badRequest("bin cannot be empty", nil, w, r)
+		data := ViewData{
+			Title:     "pastebin",
+			IsPreview: false,
+			Error:     "Bin cannot be empty",
+		}
+		w.WriteHeader(http.StatusBadRequest)
+		if err := h.templates.ExecuteTemplate(w, "base", data); err != nil {
+			internal("could not render template", err, w, r)
+		}
 		return
 	}
 
diff --git a/handler/http_test.go b/handler/http_test.go
index 6aa2b71..9d85def 100644
--- a/handler/http_test.go
+++ b/handler/http_test.go
@@ -91,6 +91,7 @@ func TestHandleSet(t *testing.T) {
 
 		h.HandleSet(rr, req)
 		assert.Equal(t, http.StatusBadRequest, rr.Code)
+		assert.Contains(t, rr.Body.String(), "Bin cannot be empty")
 	})
 
 	t.Run("Too Large", func(t *testing.T) {
@@ -102,6 +103,7 @@ func TestHandleSet(t *testing.T) {
 
 		h.HandleSet(rr, req)
 		assert.Equal(t, http.StatusBadRequest, rr.Code)
+		assert.Contains(t, rr.Body.String(), "Content too large")
 	})
 
 	t.Run("Malformed Form", func(t *testing.T) {
@@ -111,6 +113,7 @@ func TestHandleSet(t *testing.T) {
 
 		h.HandleSet(rr, req)
 		assert.Equal(t, http.StatusBadRequest, rr.Code)
+		assert.Contains(t, rr.Body.String(), "Invalid form data")
 	})
 
 	t.Run("Store Error", func(t *testing.T) {
diff --git a/view/static/style.css b/view/static/style.css
index 6a302b2..fa271d6 100644
--- a/view/static/style.css
+++ b/view/static/style.css
@@ -224,6 +224,18 @@ code.with-line-numbers {
     background: var(--secondary);
 }
 
+.error-banner {
+    background-color: rgba(248, 81, 73, 0.1);
+    border: 1px solid rgba(248, 81, 73, 0.4);
+    color: #f85149;
+    padding: 0.75rem 1rem;
+    border-radius: 6px;
+    margin-bottom: 1rem;
+    font-size: 0.85rem;
+    display: flex;
+    align-items: center;
+}
+
 .sr-only {
     position: absolute;
     width: 1px;
diff --git a/view/templates/bin.html b/view/templates/bin.html
index 5a2f051..0a33de5 100644
--- a/view/templates/bin.html
+++ b/view/templates/bin.html
@@ -60,10 +60,15 @@
     </script>
     {{ else }}
     <div class="content-wrapper">
+        {{ if .Error }}
+        <div class="error-banner">
+            {{ .Error }}
+        </div>
+        {{ end }}
         <form id="paste-form" action="/" method="post">
             <label for="content-editor" class="sr-only">Paste Content</label>
             <textarea id="content-editor" name="content" placeholder="Paste something interesting here..." autofocus
-                autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+                autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false">{{ .Content }}</textarea>
         </form>
     </div>
     <script>