Remove isEmpty (#10295)

src/document/doc-utils.js

@@ -104,10 +104,6 @@ function findInDoc(doc, fn, defaultValue) {
   return result;
 }
 
-function isEmpty(n) {
-  return typeof n === "string" && n.length === 0;
-}
-
 function isLineNextFn(doc) {
   if (typeof doc === "string") {
     return false;
@@ -382,7 +378,6 @@ function replaceNewlinesWithLiterallines(doc) {
 module.exports = {
   isConcat,
   getDocParts,
-  isEmpty,
   willBreak,
   isLineNext,
   traverseDoc,

src/language-js/print/jsx.js

@@ -14,7 +14,7 @@ const {
     lineSuffixBoundary,
     join,
   },
-  utils: { willBreak, isLineNext, isEmpty },
+  utils: { willBreak, isLineNext },
 } = require("../../document");
 
 const { getLast, getPreferredQuote } = require("../../common/util");
@@ -177,7 +177,7 @@ function printJsxElementInternal(path, options, print) {
   // Trim trailing lines (or empty strings)
   while (
     children.length > 0 &&
-    (isLineNext(getLast(children)) || isEmpty(getLast(children)))
+    (!getLast(children) || isLineNext(getLast(children)))
   ) {
     children.pop();
   }
@@ -185,8 +185,8 @@ function printJsxElementInternal(path, options, print) {
   // Trim leading lines (or empty strings)
   while (
     children.length > 0 &&
-    (isLineNext(children[0]) || isEmpty(children[0])) &&
-    (isLineNext(children[1]) || isEmpty(children[1]))
+    (!children[0] || isLineNext(children[0])) &&
+    (!children[1] || isLineNext(children[1]))
   ) {
     children.shift();
     children.shift();

src/language-js/printer-estree.js

@@ -15,7 +15,6 @@ const {
 } = require("../common/util");
 const {
   builders: { join, line, hardline, softline, literalline, group, indent },
-  utils: { isEmpty },
 } = require("../document");
 const embed = require("./embed");
 const clean = require("./clean");
@@ -97,14 +96,13 @@ const { printBlock, printBlockBody } = require("./print/block");
 const { printComment } = require("./print/comment");
 
 function genericPrint(path, options, printPath, args) {
-  const node = path.getValue();
-  let needsParens = false;
   const linesWithoutParens = printPathNoParens(path, options, printPath, args);
-
-  if (!node || isEmpty(linesWithoutParens)) {
-    return linesWithoutParens;
+  if (!linesWithoutParens) {
+    return "";
   }
 
+  let needsParens = false;
+  const node = path.getValue();
   const parentExportDecl = getParentExportDeclaration(path);
   const decorators = [];
   if (