fix(cli): handle empty-value tag edits in interactive tag prompt

internal/utils/prompts.go

@@ -252,11 +252,15 @@ var updateResourceTagsPromptFn = func(existingTags map[string]string, noColor bo
 				return nil, err
 			}
 
-			// Empty value means remove the tag
-			if value == "" && tags[key] != "" {
-				delete(tags, key)
-				fmt.Fprintf(os.Stderr, "  Removed tag: %s\n", key)
-			} else if value != "" {
+			// Empty value means remove the tag, if it exists.
+			if value == "" {
+				if _, exists := tags[key]; exists {
+					delete(tags, key)
+					fmt.Fprintf(os.Stderr, "  Removed tag: %s\n", key)
+				} else {
+					fmt.Fprintf(os.Stderr, "  Tag '%s' does not exist, nothing to remove\n", key)
+				}
+			} else {
 				tags[key] = value
 				fmt.Fprintf(os.Stderr, "  Updated tag: %s: %s\n", key, value)
 			}

internal/utils/prompts_test.go

@@ -703,6 +703,34 @@ func TestUpdateResourceTagsPrompt_DefaultModifyExistingRemovesTag(t *testing.T)
 	assert.Empty(t, stdout)
 }
 
+// TestUpdateResourceTagsPrompt_DefaultModifyRemovesEmptyValueTag exercises
+// removing an existing tag whose current value is already empty.
+func TestUpdateResourceTagsPrompt_DefaultModifyRemovesEmptyValueTag(t *testing.T) {
+	mockPromptSequence(t, []bool{true, true}, []string{"2", "foo", "", ""})
+	stdout, stderr := withMockedIO("", func() {
+		tags, err := UpdateResourceTagsPrompt(map[string]string{"foo": ""}, true)
+		assert.NoError(t, err)
+		assert.Empty(t, tags)
+	})
+	assert.Contains(t, stderr, "Removed tag: foo")
+	assert.Empty(t, stdout)
+}
+
+// TestUpdateResourceTagsPrompt_DefaultModifyEmptyValueForNewKey exercises
+// entering an empty value for a key that does not exist yet: it must not be
+// added to the tag set, and the user gets a clear "nothing to remove" notice
+// instead of the key silently vanishing.
+func TestUpdateResourceTagsPrompt_DefaultModifyEmptyValueForNewKey(t *testing.T) {
+	mockPromptSequence(t, []bool{true, true}, []string{"2", "baz", "", ""})
+	stdout, stderr := withMockedIO("", func() {
+		tags, err := UpdateResourceTagsPrompt(map[string]string{"foo": "bar"}, true)
+		assert.NoError(t, err)
+		assert.Equal(t, map[string]string{"foo": "bar"}, tags)
+	})
+	assert.Contains(t, stderr, "Tag 'baz' does not exist, nothing to remove")
+	assert.Empty(t, stdout)
+}
+
 // TestDesignConfirmPrompt_DefaultRendering verifies the default
 // designConfirmPromptFn renders design-stage wording instead of
 // BuyConfirmPrompt's purchase wording.

internal/utils/prompts_wasm.go

@@ -270,11 +270,15 @@ func wasmUpdateResourceTagsPrompt(existingTags map[string]string, noColor bool)
 			return nil, err
 		}
 
-		// Empty value means remove the tag
-		if value == "" && tags[key] != "" {
-			delete(tags, key)
-			buf.add(fmt.Sprintf("  Removed tag: %s", key))
-		} else if value != "" {
+		// Empty value means remove the tag, if it exists.
+		if value == "" {
+			if _, exists := tags[key]; exists {
+				delete(tags, key)
+				buf.add(fmt.Sprintf("  Removed tag: %s", key))
+			} else {
+				buf.add(fmt.Sprintf("  Tag '%s' does not exist, nothing to remove", key))
+			}
+		} else {
 			tags[key] = value
 			buf.add(fmt.Sprintf("  Updated tag: %s: %s", key, value))
 		}

internal/utils/prompts_wasm_test.go

@@ -389,6 +389,24 @@ func TestWasmUpdateResourceTagsPrompt(t *testing.T) {
 			},
 			expectError: false,
 		},
+		{
+			name: "empty value for key that does not exist is a no-op",
+			existingTags: map[string]string{
+				"foo": "bar",
+			},
+			mockResponses: []string{
+				"y",   // Continue
+				"2",   // Start with existing
+				"baz", // Key that does not exist
+				"",    // Empty value = attempt remove
+				"",    // Finish
+				"y",   // Apply changes
+			},
+			expectedTags: map[string]string{
+				"foo": "bar",
+			},
+			expectError: false,
+		},
 		{
 			name:         "no existing tags - add new",
 			existingTags: map[string]string{},