Don't append extra newline when using |indent filter

Fixes #1231

CHANGELOG.md

@@ -21,6 +21,8 @@ Changelog
 * Fix bug that prevented errors in included templates from being raised when
   rendering templates synchronously. Fixes
   [#1272](https://github.com/mozilla/nunjucks/pull/1276).
+* The `indent` filter no longer appends an additional newline. Fixes
+  [#1231](https://github.com/mozilla/nunjucks/issues/1231).
 
 3.2.1 (Mar 17 2020)
 -------------------

nunjucks/src/filters.js

@@ -182,8 +182,8 @@ function indent(str, width, indentfirst) {
   const sp = lib.repeat(' ', width);
 
   const res = lines.map((l, i) => {
-    return (i === 0 && !indentfirst) ? `${l}\n` : `${sp}${l}\n`;
-  }).join('');
+    return (i === 0 && !indentfirst) ? l : `${sp}${l}`;
+  }).join('\n');
 
   return r.copySafeness(str, res);
 }

tests/filters.js

@@ -405,15 +405,15 @@
 
     it('indent', function(done) {
       equal('{{ "one\ntwo\nthree" | indent }}',
-        'one\n    two\n    three\n');
+        'one\n    two\n    three');
       equal('{{ "one\ntwo\nthree" | indent(2) }}',
-        'one\n  two\n  three\n');
+        'one\n  two\n  three');
       equal('{{ "one\ntwo\nthree" | indent(2, true) }}',
-        '  one\n  two\n  three\n');
+        '  one\n  two\n  three');
 
       equal('{{ str | indent }}', {
         str: r.markSafe('one\ntwo\nthree')
-      }, 'one\n    two\n    three\n');
+      }, 'one\n    two\n    three');
 
       equal('{{ "" | indent }}', '');
       equal('{{ undefined | indent }}', '');