util: do not escape single quotes if not necessary

Right now util.inspect will always escape single quotes. That is not
necessary though in case the string that will be escaped does not
contain double quotes. In that case the string can simply be wrapped
in double quotes instead.
If the string contains single and double quotes and it does not
contain `${` as part of the string, backticks will be used instead.
That makes sure only very few strings have to escape quotes at all.
Thus it increases the readability of these strings.

PR-URL: https://github.com/nodejs/node/pull/21624
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index f97ab95cde..e0dceb60f7 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -47,7 +47,7 @@ assert.strictEqual(util.inspect(new Date('')), (new Date('')).toString());
 assert.strictEqual(util.inspect('\n\u0001'), "'\\n\\u0001'");
 assert.strictEqual(
   util.inspect(`${Array(75).fill(1)}'\n\u001d\n\u0003`),
-  `'${Array(75).fill(1)}\\'\\n\\u001d\\n\\u0003'`
+  `"${Array(75).fill(1)}'\\n\\u001d\\n\\u0003"`
 );
 assert.strictEqual(util.inspect([]), '[]');
 assert.strictEqual(util.inspect(Object.create([])), 'Array {}');
@@ -1424,3 +1424,9 @@ util.inspect(process);
   assert(longList.includes('[Object: Inspection interrupted ' +
     'prematurely. Maximum call stack size exceeded.]'));
 }
+
+// Do not escape single quotes if no double quote or backtick is present.
+assert.strictEqual(util.inspect("'"), '"\'"');
+assert.strictEqual(util.inspect('"\''), '`"\'`');
+// eslint-disable-next-line no-template-curly-in-string
+assert.strictEqual(util.inspect('"\'${a}'), "'\"\\'${a}'");