fix: improve prefer-template fixer

Fixes #15083
eslint · Oct 28, 2021 · 9ee0532 · 9ee0532
1 parent a86ffc0
commit 9ee0532
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/lib/rules/prefer-template.js b/lib/rules/prefer-template.js
@@ -88,6 +88,20 @@ function hasNonStringLiteral(node) {
     return !astUtils.isStringLiteral(node);
 }
 
+/**
+ * Checks whether or not a given binary expression has an identifier reference.
+ * @param {ASTNode} node A node to check.
+ * @returns {boolean} `true` if the node has identifier reference.
+ */
+function hasIdentifierReference(node) {
+    if (isConcatenation(node)) {
+
+        // `left` is deeper than `right` normally.
+        return hasNonStringLiteral(node.right) || hasNonStringLiteral(node.left);
+    }
+    return node.type === "Identifier";
+}
+
 /**
  * Determines whether a given node will start with a template curly expression (`${}`) when being converted to a template literal.
  * @param {ASTNode} node The node that will be fixed to a template literal
@@ -187,6 +201,14 @@ module.exports = {
                 return sourceCode.getText(currentNode);
             }
 
+            if (isConcatenation(currentNode) && !hasIdentifierReference(currentNode)) {
+
+                // eslint-disable-next-line require-unicode-regexp -- `"Hello " + "World"` -> `Hello World`
+                const concatenatedText = sourceCode.getText(currentNode).split("+").map(e => e.trim()).join("").replace(/"/g, "");
+
+                return `\`${concatenatedText}\``;
+            }
+
             if (isConcatenation(currentNode) && hasStringLiteral(currentNode) && hasNonStringLiteral(currentNode)) {
                 const plusSign = sourceCode.getFirstTokenBetween(currentNode.left, currentNode.right, token => token.value === "+");
                 const textBeforePlus = getTextBetween(currentNode.left, plusSign);