From 26ec217ed78bbbd86ca8e952bc568eb9aaba51b1 Mon Sep 17 00:00:00 2001
From: alina sireneva <alina@tei.su>
Date: Sun, 23 Mar 2025 23:06:46 +0300
Subject: [PATCH] feat(markdown-parser)!: support quotes

---
 packages/markdown-parser/src/index.ts         | 32 +++++++++++++++++++
 .../src/markdown-parser.test.ts               | 14 ++++++++
 2 files changed, 46 insertions(+)

diff --git a/packages/markdown-parser/src/index.ts b/packages/markdown-parser/src/index.ts
index 5d06d3b6..b2d9e4b3 100644
--- a/packages/markdown-parser/src/index.ts
+++ b/packages/markdown-parser/src/index.ts
@@ -144,6 +144,8 @@ function parse(
     let insideCode = false
     let insidePre = false
     let insideLink = false
+    let currentBlockquoteStart: number | null = null
+    let prevBlockquote: tl.Mutable<tl.RawMessageEntityBlockquote> | null = null
 
     let insideLinkUrl = false
     let pendingLinkUrl = ''
@@ -392,6 +394,34 @@ function parse(
                 } else {
                     pos = len
                 }
+
+                if (currentBlockquoteStart != null) {
+                    const prevEnd = prevBlockquote ? prevBlockquote.offset + prevBlockquote.length : Number.NaN
+                    if (currentBlockquoteStart - 1 === prevEnd) {
+                        // extend the previous entity
+                        prevBlockquote!.length += result.length - currentBlockquoteStart
+                    } else {
+                        if (prevBlockquote) entities.push(prevBlockquote)
+                        prevBlockquote = {
+                            _: 'messageEntityBlockquote',
+                            offset: currentBlockquoteStart,
+                            length: result.length - currentBlockquoteStart - 1,
+                        }
+                    }
+                    currentBlockquoteStart = null
+                }
+                continue
+            }
+
+            if (c === '>' && (result.length === 0 || result[result.length - 1] === '\n')) {
+                currentBlockquoteStart = result.length
+                pos += 1
+                continue
+            }
+
+            if (c === ' ' && currentBlockquoteStart === result.length) {
+                // ignore spaces after `>`
+                pos += 1
                 continue
             }
 
@@ -443,6 +473,8 @@ function parse(
 
     feed(strings[strings.length - 1])
 
+    if (prevBlockquote) entities.push(prevBlockquote)
+
     function adjustOffsets(from: number, by: number): void {
         for (const ent of entities) {
             if (ent.offset >= from) ent.offset += by
diff --git a/packages/markdown-parser/src/markdown-parser.test.ts b/packages/markdown-parser/src/markdown-parser.test.ts
index 8ba8392e..032f2e33 100644
--- a/packages/markdown-parser/src/markdown-parser.test.ts
+++ b/packages/markdown-parser/src/markdown-parser.test.ts
@@ -620,6 +620,20 @@ ${'meowww'}
             )
         })
 
+        it('should handle quotes', () => {
+            test(
+                md_`
+some text :3
+> btw i like ${'quotes'}
+> and also **formatting**
+>   :3
+some more text
+`,
+                [createEntity('messageEntityBold', 40, 10), createEntity('messageEntityBlockquote', 13, 40)],
+                'some text :3\nbtw i like quotes\nand also formatting\n:3\nsome more text',
+            )
+        })
+
         it('should interpolate inside links', () => {
             test(
                 md_`[${'link'}](${'https'}://example.com/\\)${'foo'}/bar/${'baz'}?foo=bar&baz=${'egg'})`,