Support function and variable declarations after the final return in components-return-once, valid because of hoisting. Closes #163.

Author: joshwilsonvu

packages/eslint-plugin-solid/src/rules/components-return-once.ts

@@ -61,8 +61,9 @@ export default createRule({
     const onFunctionEnter = (node: FunctionNode) => {
       let lastReturn: T.ReturnStatement | undefined;
       if (node.body.type === "BlockStatement") {
-        const { length } = node.body.body;
-        const last = length && node.body.body[length - 1];
+        // find last statement, ignoring function/class/variable declarations (hoisting)
+        const last = node.body.body.findLast((node) => !node.type.endsWith("Declaration"));
+        // if it's a return, store it
         if (last && last.type === "ReturnStatement") {
           lastReturn = last;
         }
@@ -153,7 +154,7 @@ export default createRule({
               return fixer.replaceText(argument, `<>${putIntoJSX(argument)}</>`);
             },
           });
-        } else if (argument?.type === "LogicalExpression")
+        } else if (argument?.type === "LogicalExpression") {
           if (argument.operator === "&&") {
             const sourceCode = getSourceCode(context);
             // we have a `return condition && expression`--put that in a <Show />
@@ -175,6 +176,7 @@ export default createRule({
               messageId: "noConditionalReturn",
             });
           }
+        }
       }
 
       // Pop on exit

packages/eslint-plugin-solid/test/rules/components-return-once.test.ts

@@ -49,6 +49,20 @@ export const cases = run("components-return-once", rule, {
       };
       return <></>;
     }`,
+    `function Component() {
+      return <>{hoisted()}</>;
+      function hoisted() {
+        return 'hoisted';
+      }
+    }`,
+    `function Component() {
+      return <></>;
+      const hoisted = 'hoisted';
+    }`,
+    `function Component() {
+      return <></>;
+      class Hoisted {}
+    }`,
   ],
   invalid: [
     // Early returns
@@ -70,6 +84,16 @@ export const cases = run("components-return-once", rule, {
       }`,
       errors: [{ messageId: "noEarlyReturn" }],
     },
+    {
+      code: `const Component = () => {
+        if (condition) {
+          return <div />;
+        }
+        return <span />;
+        function hoisted() {}
+      }`,
+      errors: [{ messageId: "noEarlyReturn" }],
+    },
     // Balanced ternaries
     {
       code: `function Component() {