test: cover remaining blank-line branches

Author: kaelzhang

src/stringify.js

@@ -109,9 +109,7 @@ const process_comments = (host, symbol_tag, deeper_gap, display_block) => {
   })
 
   if (!last_comment) {
-    return blank_lines
-      ? repeat_line_breaks(blank_lines + 1, deeper_gap)
-      : EMPTY
+    return repeat_line_breaks(blank_lines + 1, deeper_gap)
   }
 
   const default_line_breaks_after = display_block

test/remove-blank-lines.test.js

@@ -85,3 +85,55 @@ test('removeBlankLines: should return early if the location does not exist', t =
 
   t.deepEqual(obj, {foo: 1})
 })
+
+test('removeBlankLines: should return early when location has no blank lines', t => {
+  const obj = parse(`{
+  // before foo
+  "foo": 1
+}`)
+
+  removeBlankLines(obj, {where: 'before', key: 'foo'})
+
+  t.is(stringify(obj, null, 2), `{
+  // before foo
+  "foo": 1
+}`)
+})
+
+test('removeBlankLines: should ignore non-array comment slots', t => {
+  const obj = {foo: 1}
+
+  Object.defineProperty(obj, Symbol.for('before:foo'), {
+    value: 'not-an-array',
+    writable: true,
+    configurable: true
+  })
+
+  removeBlankLines(obj, {where: 'before', key: 'foo'})
+
+  t.is(obj[Symbol.for('before:foo')], 'not-an-array')
+})
+
+test('removeBlankLines: should ignore non-comment symbols during recursive cleanup', t => {
+  const obj = parse(`{
+  // before foo
+
+  "foo": 1
+}`)
+  const marker = Symbol('marker')
+
+  Object.defineProperty(obj, marker, {
+    value: [{type: 'BlankLine', inline: false}],
+    writable: true,
+    configurable: true
+  })
+
+  removeBlankLines(obj)
+
+  t.true(Object.hasOwn(obj, marker))
+  t.deepEqual(obj[marker], [{type: 'BlankLine', inline: false}])
+  t.is(stringify(obj, null, 2), `{
+  // before foo
+  "foo": 1
+}`)
+})

test/stringify.test.js

@@ -340,6 +340,60 @@ test('render explicit BlankLine tokens mixed with inline comments', t => {
 }`)
 })
 
+test('render BlankLine tokens before inline comments', t => {
+  const comments = [
+    {
+      type: 'BlankLine',
+      inline: false
+    },
+    {
+      type: 'BlockComment',
+      value: ' second ',
+      inline: true
+    }
+  ]
+
+  const obj = {
+    a: 1,
+    b: 2
+  }
+
+  Object.defineProperty(obj, Symbol.for('after:a'), {
+    value: comments,
+    writable: true,
+    configurable: true
+  })
+
+  const output = stringify(obj, null, 2)
+
+  t.is(output, `{
+  "a": 1,
+  /* second */
+  "b": 2
+}`)
+})
+
+test('ignore blank-line-only before-all slots when stringifying root output', t => {
+  const obj = {
+    a: 1
+  }
+
+  Object.defineProperty(obj, Symbol.for('before-all'), {
+    value: [
+      {
+        type: 'BlankLine',
+        inline: false
+      }
+    ],
+    writable: true,
+    configurable: true
+  })
+
+  t.is(stringify(obj, null, 2), `{
+  "a": 1
+}`)
+})
+
 test('escape control characters same as JSON.stringify', t => {
   for (let i = 0; i <= 0x1f; i ++) {
     const char = String.fromCharCode(i)