From cfd3b63b9bb87395b9725e676372cc090d3c66d1 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Thu, 24 Oct 2019 11:54:50 +0800
Subject: [PATCH] warn if using svelte:options tag without
 compile_options.customElement

---
 src/compiler/compile/Component.ts               |  7 +++++++
 .../input.svelte                                |  1 +
 .../warnings.json                               | 17 +++++++++++++++++
 3 files changed, 25 insertions(+)
 create mode 100644 test/validator/samples/missing-custom-element-compile-options/input.svelte
 create mode 100644 test/validator/samples/missing-custom-element-compile-options/warnings.json

diff --git a/src/compiler/compile/Component.ts b/src/compiler/compile/Component.ts
index b22b351da057..e76696c53d92 100644
--- a/src/compiler/compile/Component.ts
+++ b/src/compiler/compile/Component.ts
@@ -1307,6 +1307,13 @@ function process_component_options(component: Component, nodes) {
 							});
 						}
 
+						if (tag && !component.compile_options.customElement) {
+							component.warn(attribute, {
+								code: 'missing-custom-element-compile-options',
+								message: `tag name is used when compiling the compenent as a custom element. Did you forgot to add "customElement" for compile options?`
+							});
+						}
+
 						component_options.tag = tag;
 						break;
 					}
diff --git a/test/validator/samples/missing-custom-element-compile-options/input.svelte b/test/validator/samples/missing-custom-element-compile-options/input.svelte
new file mode 100644
index 000000000000..94ecce3ef64e
--- /dev/null
+++ b/test/validator/samples/missing-custom-element-compile-options/input.svelte
@@ -0,0 +1 @@
+<svelte:options tag="custom-element" />
\ No newline at end of file
diff --git a/test/validator/samples/missing-custom-element-compile-options/warnings.json b/test/validator/samples/missing-custom-element-compile-options/warnings.json
new file mode 100644
index 000000000000..a4c52792abf1
--- /dev/null
+++ b/test/validator/samples/missing-custom-element-compile-options/warnings.json
@@ -0,0 +1,17 @@
+[
+	{
+		"code": "missing-custom-element-compile-options",
+		"end": {
+			"character": 36,
+			"column": 36,
+			"line": 1
+		},
+		"message": "tag name is used when compiling the compenent as a custom element. Did you forgot to add \"customElement\" for compile options?",
+		"pos": 16,
+		"start": {
+			"character": 16,
+			"column": 16,
+			"line": 1
+		}
+	}
+]