Port jsx-ast-util's checking for spread object props, simplify jsx-no-duplicate-props.

Author: joshwilsonvu

src/rules/jsx-no-duplicate-props.ts

@@ -1,4 +1,5 @@
 import { TSESTree as T, ESLintUtils } from "@typescript-eslint/utils";
+import { jsxGetAllProps } from "../utils";
 
 const createRule = ESLintUtils.RuleCreator.withoutDocs;
 
@@ -58,27 +59,9 @@ export default createRule<Options, MessageIds>({
           props.add(name);
         };
 
-        node.attributes.forEach((decl) => {
-          if (decl.type === "JSXSpreadAttribute") {
-            if (decl.argument.type === "ObjectExpression") {
-              for (const prop of decl.argument.properties) {
-                if (prop.type === "Property") {
-                  if (prop.key.type === "Identifier") {
-                    checkPropName(prop.key.name, prop.key);
-                  } else if (prop.key.type === "Literal") {
-                    checkPropName(String(prop.key.value), prop.key);
-                  }
-                }
-              }
-            }
-          } else {
-            const name =
-              decl.name.type === "JSXNamespacedName"
-                ? `${decl.name.namespace.name}:${decl.name.name.name}`
-                : decl.name.name;
-            checkPropName(name, decl.name);
-          }
-        });
+        for (const [name, propNode] of jsxGetAllProps(node.attributes)) {
+          checkPropName(name, propNode);
+        }
 
         const hasChildrenProp = props.has("children");
         const hasChildren = (node.parent as T.JSXElement | T.JSXFragment).children.length > 0;

src/utils.ts

@@ -222,24 +222,44 @@ export function removeSpecifier(
 }
 
 export function jsxPropName(prop: T.JSXAttribute) {
-  if (!prop.type || prop.type !== "JSXAttribute") {
-    throw new Error("The prop must be a JSXAttribute collected by the AST parser.");
-  }
-
   if (prop.name.type === "JSXNamespacedName") {
     return `${prop.name.namespace.name}:${prop.name.name.name}`;
   }
 
   return prop.name.name;
 }
 
-export function jsxHasProp(props: (T.JSXAttribute | T.JSXSpreadAttribute)[], prop: string) {
-  return props.some(
-    (attribute) => attribute.type !== "JSXSpreadAttribute" && prop === jsxPropName(attribute)
-  );
+type Props = T.JSXOpeningElement["attributes"];
+
+/** Iterate through both attributes and spread object props, yielding the name and the node. */
+export function* jsxGetAllProps(props: Props): Generator<[string, T.Node]> {
+  for (const attr of props) {
+    if (attr.type === "JSXSpreadAttribute" && attr.argument.type === "ObjectExpression") {
+      for (const property of attr.argument.properties) {
+        if (property.type === "Property") {
+          if (property.key.type === "Identifier") {
+            yield [property.key.name, property.key];
+          } else if (property.key.type === "Literal") {
+            yield [String(property.key.value), property.key];
+          }
+        }
+      }
+    } else if (attr.type === "JSXAttribute") {
+      yield [jsxPropName(attr), attr.name];
+    }
+  }
+}
+
+/** Returns whether an element has a prop, checking spread object props. */
+export function jsxHasProp(props: Props, prop: string) {
+  for (const [p] of jsxGetAllProps(props)) {
+    if (p === prop) return true;
+  }
+  return false;
 }
 
-export function jsxGetProp(props: (T.JSXAttribute | T.JSXSpreadAttribute)[], prop: string) {
+/** Get a JSXAttribute, excluding spread props. */
+export function jsxGetProp(props: Props, prop: string) {
   return props.find(
     (attribute) => attribute.type !== "JSXSpreadAttribute" && prop === jsxPropName(attribute)
   ) as T.JSXAttribute | undefined;