[Fix] jsx-indent: Fix false positive when a jsx element is the last…

… statement within a do expression

Fixes #2199.

lib/rules/jsx-indent.js

@@ -195,6 +195,56 @@ module.exports = {
       );
     }
 
+    /**
+     * Check if the node is the last statement within a do expression
+     * @param {ASTNode} node The node to check
+     * @return {Boolean} true if its the case, false if not
+     */
+    function isLastExpInDoExp(node) {
+      /*
+        Detect the structure below:
+        DoExpression {
+          body: (
+            BlockStatement {
+              body: [
+                (...),
+                ExpressionStatement {
+                  body: (
+                    JSXElement {
+                      openingElement: (node)
+                    }
+                  )
+                }
+              ]
+            }
+          )
+        }
+      */
+      const isInExpStmt = (
+        node.parent &&
+        node.parent.parent &&
+        node.parent.parent.type === 'ExpressionStatement'
+      );
+      if (!isInExpStmt) {
+        return false;
+      }
+
+      const expStmt = node.parent.parent;
+      const isInBlockStmtWithinDoExp = (
+        expStmt.parent &&
+        expStmt.parent.type === 'BlockStatement' &&
+        expStmt.parent.parent &&
+        expStmt.parent.parent.type === 'DoExpression'
+      );
+      if (!isInBlockStmtWithinDoExp) {
+        return false;
+      }
+
+      const blockStmt = expStmt.parent;
+      const blockStmtLastElm = blockStmt.body[blockStmt.body.length - 1];
+      return blockStmtLastElm === expStmt;
+    }
+
     /**
      * Check indent for nodes list
      * @param {ASTNode} node The node to check
@@ -239,7 +289,8 @@ module.exports = {
       const indent = (
         prevToken.loc.start.line === node.loc.start.line ||
         isRightInLogicalExp(node) ||
-        isAlternateInConditionalExp(node)
+        isAlternateInConditionalExp(node) ||
+        isLastExpInDoExp(node)
       ) ? 0 : indentSize;
       checkNodesIndent(node, parentElementIndent + indent);
     }