Fix no-danger-with-children to ignore line breaks (fixes #1262)

Author: yannickcr

lib/rules/no-danger-with-children.js

@@ -64,11 +64,24 @@ module.exports = {
       });
     }
 
+    /**
+     * Checks to see if a node is a line break
+     * @param {ASTNode} node The AST node being checked
+     * @returns {Boolean} True if node is a line break, false if not
+     */
+    function isLineBreak(node) {
+      const isLiteral = node.type === 'Literal';
+      const isMultiline = node.loc.start.line !== node.loc.end.line;
+      const isWhiteSpaces = /^\s*$/.test(node.value);
+
+      return isLiteral && isMultiline && isWhiteSpaces;
+    }
+
     return {
       JSXElement: function (node) {
         let hasChildren = false;
 
-        if (node.children.length) {
+        if (node.children.length && !isLineBreak(node.children[0])) {
           hasChildren = true;
         } else if (findJsxProp(node, 'children')) {
           hasChildren = true;

tests/lib/rules/no-danger-with-children.js

@@ -68,6 +68,12 @@ ruleTester.run('no-danger-with-children', rule, {
     {
       code: '<Hello dangerouslySetInnerHTML={{ __html: "HTML" }} />'
     },
+    {
+      code: `
+        <Hello dangerouslySetInnerHTML={{ __html: "HTML" }}>
+        </Hello>
+      `
+    },
     {
       code: 'React.createElement("div", { dangerouslySetInnerHTML: { __html: "HTML" } });'
     },
@@ -120,6 +126,10 @@ ruleTester.run('no-danger-with-children', rule, {
       code: '<Hello dangerouslySetInnerHTML={{ __html: "HTML" }} children="Children" />',
       errors: [{message: 'Only set one of `children` or `props.dangerouslySetInnerHTML`'}]
     },
+    {
+      code: '<Hello dangerouslySetInnerHTML={{ __html: "HTML" }}> </Hello>',
+      errors: [{message: 'Only set one of `children` or `props.dangerouslySetInnerHTML`'}]
+    },
     {
       code: [
         'React.createElement(',