1 files changed, 123 insertions, 0 deletions
diff --git a/__tests__/lib/strings/rich-text-sanitize.ts b/__tests__/lib/strings/rich-text-sanitize.ts
new file mode 100644
index 000000000..d0bbae5e8
--- /dev/null
+++ b/__tests__/lib/strings/rich-text-sanitize.ts
@@ -0,0 +1,123 @@
+import {AppBskyFeedPost} from '@atproto/api'
+type Entity = AppBskyFeedPost.Entity
+import {RichText} from '../../../src/lib/strings/rich-text'
+import {removeExcessNewlines} from '../../../src/lib/strings/rich-text-sanitize'
+
+describe('removeExcessNewlines', () => {
+  it('removes more than two consecutive new lines', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\n\n\n\n\n\ntest\n\n\n\n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with spaces', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n \n \n \n \n\n\ntest\n\n\n\n\n\n\ntest\n\n\n\n\n  \n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('returns original string if there are no consecutive new lines', () => {
+    const input = new RichText('test\n\ntest\n\ntest\n\ntest\n\ntest')
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual(input.text)
+  })
+
+  it('returns original string if there are no new lines', () => {
+    const input = new RichText('test test          test test test')
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual(input.text)
+  })
+
+  it('returns empty string if input is empty', () => {
+    const input = new RichText('')
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('')
+  })
+
+  it('works with different types of new line characters', () => {
+    const input = new RichText(
+      'test\r\ntest\n\rtest\rtest\n\n\n\ntest\n\r \n \n \n \n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\r\ntest\n\rtest\rtest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with zero width space', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\u200B\u200B\n\n\n\ntest\n \u200B\u200B \n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with zero width non-joiner', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\u200C\u200C\n\n\n\ntest\n \u200C\u200C \n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with zero width joiner', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\u200D\u200D\n\n\n\ntest\n \u200D\u200D \n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with soft hyphen', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\u00AD\u00AD\n\n\n\ntest\n \u00AD\u00AD \n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+
+  it('removes more than two consecutive new lines with word joiner', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\u2060\u2060\n\n\n\ntest\n \u2060\u2060 \n\n\n\ntest\n\n\n\n\n\n\ntest',
+    )
+    const output = removeExcessNewlines(input)
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+  })
+})
+
+describe('removeExcessNewlines w/entities', () => {
+  it('preserves entities as expected', () => {
+    const input = new RichText(
+      'test\n\n\n\n\ntest\n\n\n\n\n\n\ntest\n\n\n\n\n\n\ntest\n\n\n\n\n\n\ntest',
+      [
+        {index: {start: 0, end: 13}, type: '', value: ''},
+        {index: {start: 13, end: 24}, type: '', value: ''},
+        {index: {start: 9, end: 15}, type: '', value: ''},
+        {index: {start: 4, end: 9}, type: '', value: ''},
+      ],
+    )
+    const output = removeExcessNewlines(input)
+    expect(entToStr(input.text, input.entities?.[0])).toEqual(
+      'test\n\n\n\n\ntest',
+    )
+    expect(entToStr(input.text, input.entities?.[1])).toEqual(
+      '\n\n\n\n\n\n\ntest',
+    )
+    expect(entToStr(input.text, input.entities?.[2])).toEqual('test\n\n')
+    expect(entToStr(input.text, input.entities?.[3])).toEqual('\n\n\n\n\n')
+    expect(output.text).toEqual('test\n\ntest\n\ntest\n\ntest\n\ntest')
+    expect(entToStr(output.text, output.entities?.[0])).toEqual('test\n\ntest')
+    expect(entToStr(output.text, output.entities?.[1])).toEqual('test')
+    expect(entToStr(output.text, output.entities?.[2])).toEqual('test')
+    expect(output.entities?.[3]).toEqual(undefined)
+  })
+})
+
+function entToStr(str: string, ent?: Entity) {
+  if (!ent) {
+    return ''
+  }
+  return str.slice(ent.index.start, ent.index.end)
+}