From f8eee243dd48f3d432ec0b33decdc45fa9f8dc0e Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <dg@domgan.com>
Date: Thu, 5 Dec 2024 12:56:08 +0000
Subject: [PATCH] todos

---
 .../98-reference/.generated/compile-errors.md | 18 +++++++++++++
 .../svelte/messages/compile-errors/script.md  | 12 +++++++++
 packages/svelte/src/compiler/errors.js        | 27 +++++++++++++++++++
 .../2-analyze/visitors/CallExpression.js      |  8 +++---
 4 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/documentation/docs/98-reference/.generated/compile-errors.md b/documentation/docs/98-reference/.generated/compile-errors.md
index 3bd162d8d7..b017fd4fb7 100644
--- a/documentation/docs/98-reference/.generated/compile-errors.md
+++ b/documentation/docs/98-reference/.generated/compile-errors.md
@@ -958,6 +958,24 @@ A `<textarea>` can have either a value attribute or (equivalently) child content
 `<title>` can only contain text and {tags}
 ```
 
+### trace_rune_duplicate
+
+```
+`$track` must only be used once within the same block statement
+```
+
+### trace_rune_invalid_argument
+
+```
+`$track` requires a string argument for the trace name
+```
+
+### trace_rune_invalid_location
+
+```
+`$track` must be placed directly inside a block statement
+```
+
 ### transition_conflict
 
 ```
diff --git a/packages/svelte/messages/compile-errors/script.md b/packages/svelte/messages/compile-errors/script.md
index 69007bfb59..2a11d8a546 100644
--- a/packages/svelte/messages/compile-errors/script.md
+++ b/packages/svelte/messages/compile-errors/script.md
@@ -186,6 +186,18 @@ It's possible to export a snippet from a `<script module>` block, but only if it
 
 Using a `$` prefix to refer to the value of a store is only possible inside `.svelte` files, where Svelte can automatically create subscriptions when a component is mounted and unsubscribe when the component is unmounted. Consider migrating to runes instead.
 
+## trace_rune_duplicate
+
+> `$track` must only be used once within the same block statement
+
+## trace_rune_invalid_argument
+
+> `$track` requires a string argument for the trace name
+
+## trace_rune_invalid_location
+
+> `$track` must be placed directly inside a block statement
+
 ## typescript_invalid_feature
 
 > TypeScript language features like %feature% are not natively supported, and their use is generally discouraged. Outside of `<script>` tags, these features are not supported. For use within `<script>` tags, you will need to use a preprocessor to convert it to JavaScript before it gets passed to the Svelte compiler. If you are using `vitePreprocess`, make sure to specifically enable preprocessing script tags (`vitePreprocess({ script: true })`)
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index 901ea1983e..a52b866250 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -469,6 +469,33 @@ export function store_invalid_subscription_module(node) {
 	e(node, "store_invalid_subscription_module", "Cannot reference store value outside a `.svelte` file");
 }
 
+/**
+ * `$track` requires a string argument for the trace name
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function trace_rune_invalid_argument(node) {
+	e(node, "trace_rune_invalid_argument", "`$track` requires a string argument for the trace name");
+}
+
+/**
+ * `$track` must be placed directly inside a block statement
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function trace_rune_invalid_location(node) {
+	e(node, "trace_rune_invalid_location", "`$track` must be placed directly inside a block statement");
+}
+
+/**
+ * `$track` must only be used once within the same block statement
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function trace_rune_duplicate(node) {
+	e(node, "trace_rune_duplicate", "`$track` must only be used once within the same block statement");
+}
+
 /**
  * TypeScript language features like %feature% are not natively supported, and their use is generally discouraged. Outside of `<script>` tags, these features are not supported. For use within `<script>` tags, you will need to use a preprocessor to convert it to JavaScript before it gets passed to the Svelte compiler. If you are using `vitePreprocess`, make sure to specifically enable preprocessing script tags (`vitePreprocess({ script: true })`)
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/CallExpression.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/CallExpression.js
index 2d35fdea2e..89a59b25db 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/CallExpression.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/CallExpression.js
@@ -141,18 +141,16 @@ export function CallExpression(node, context) {
 				e.rune_invalid_arguments_length(node, rune, 'exactly one argument');
 			}
 			if (node.arguments[0].type !== 'Literal' || typeof node.arguments[0].value !== 'string') {
-				throw new Error('TODO: $track requires a string argument');
+				e.trace_rune_invalid_argument(node);
 			}
 			if (parent.type !== 'ExpressionStatement' || context.path.at(-2)?.type !== 'BlockStatement') {
-				throw new Error('TODO: $track must be inside a block statement');
+				e.trace_rune_invalid_location(node);
 			}
-
 			if (context.state.scope.tracing) {
-				throw new Error('TODO: $track must only be used once within the same block statement');
+				e.trace_rune_duplicate(node);
 			}
 
 			if (dev) {
-				// TODO should we validate if tracing is already enabled in this or a parent scope?
 				context.state.scope.tracing = node.arguments[0].value;
 			}