From 2680e80adb56c0a445035c1b75d9e49cb5c62da2 Mon Sep 17 00:00:00 2001
From: Seiya <20365512+seiyab@users.noreply.github.com>
Date: Wed, 10 Jun 2026 23:32:38 +0900
Subject: [PATCH] Add regression tests for Markdown (#19335)
---
.../__snapshots__/format.test.js.snap | 97 +++++++++
tests/format/markdown/emphasis/issue-15032.md | 7 +
tests/format/markdown/emphasis/issue-16160.md | 3 +
tests/format/markdown/emphasis/issue-17286.md | 2 +
tests/format/markdown/emphasis/issue-3837.md | 2 +
tests/format/markdown/emphasis/issue-6112.md | 5 +
.../__snapshots__/format.test.js.snap | 41 ++++
.../markdown/fenced-code-block/issue-17300.md | 15 ++
.../__snapshots__/format.test.js.snap | 10 +-
.../parser-regression}/format.test.js | 0
.../link/parser-regression/issue-6078.md | 1 +
.../__snapshots__/format.test.js.snap | 190 ++++++++++++++++++
.../list/parser-regression/format.test.js | 1 +
.../list/parser-regression/issue-10063.md | 33 +++
.../list/parser-regression/issue-11202.md | 8 +
.../list/parser-regression/issue-12677.md | 9 +
.../issue-19146.md | 0
.../list/parser-regression/issue-19152.md | 2 +
.../list/parser-regression/issue-7474.md | 3 +
.../math/__snapshots__/format.test.js.snap | 26 +++
tests/format/markdown/math/issue-12793.md | 1 +
tests/format/markdown/math/issue-16664.md | 1 +
22 files changed, 450 insertions(+), 7 deletions(-)
create mode 100644 tests/format/markdown/emphasis/issue-15032.md
create mode 100644 tests/format/markdown/emphasis/issue-16160.md
create mode 100644 tests/format/markdown/emphasis/issue-17286.md
create mode 100644 tests/format/markdown/emphasis/issue-3837.md
create mode 100644 tests/format/markdown/emphasis/issue-6112.md
create mode 100644 tests/format/markdown/fenced-code-block/issue-17300.md
rename tests/format/markdown/{list/issue-19146 => link/parser-regression}/__snapshots__/format.test.js.snap (77%)
rename tests/format/markdown/{list/issue-19146 => link/parser-regression}/format.test.js (100%)
create mode 100644 tests/format/markdown/link/parser-regression/issue-6078.md
create mode 100644 tests/format/markdown/list/parser-regression/__snapshots__/format.test.js.snap
create mode 100644 tests/format/markdown/list/parser-regression/format.test.js
create mode 100644 tests/format/markdown/list/parser-regression/issue-10063.md
create mode 100644 tests/format/markdown/list/parser-regression/issue-11202.md
create mode 100644 tests/format/markdown/list/parser-regression/issue-12677.md
rename tests/format/markdown/list/{issue-19146 => parser-regression}/issue-19146.md (100%)
create mode 100644 tests/format/markdown/list/parser-regression/issue-19152.md
create mode 100644 tests/format/markdown/list/parser-regression/issue-7474.md
create mode 100644 tests/format/markdown/math/issue-12793.md
create mode 100644 tests/format/markdown/math/issue-16664.md
diff --git a/tests/format/markdown/emphasis/__snapshots__/format.test.js.snap b/tests/format/markdown/emphasis/__snapshots__/format.test.js.snap
index 7d8dec416..8c269c4b4 100644
--- a/tests/format/markdown/emphasis/__snapshots__/format.test.js.snap
+++ b/tests/format/markdown/emphasis/__snapshots__/format.test.js.snap
@@ -32,6 +32,103 @@ _bug_?
================================================================================
`;
+exports[`issue-3837.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+5 * 10
+a * b * c
+
+=====================================output=====================================
+5 * 10 a * b * c
+
+================================================================================
+`;
+
+exports[`issue-6112.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+*[Italic link](../_link_including_underscores_.md)*
+
+---
+
+_[Italic link](../_link_including_underscores_.md)_
+
+=====================================output=====================================
+_[Italic link](../_link_including_underscores_.md)_
+
+---
+
+_[Italic link](../_link_including_underscores_.md)_
+
+================================================================================
+`;
+
+exports[`issue-15032.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+1: The **exponentiation (\`**\`)** operator.
+
+2: The *exponentiation (\`*\`)* operator.
+
+3: The _exponentiation (\`_\`)_ operator.
+
+4: The __exponentiation (\`__\`)__ operator.
+
+=====================================output=====================================
+1: The **exponentiation (\`**\`)** operator.
+
+2: The _exponentiation (\`*\`)_ operator.
+
+3: The _exponentiation (\`_\`)_ operator.
+
+4: The **exponentiation (\`__\`)** operator.
+
+================================================================================
+`;
+
+exports[`issue-16160.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+- style\\_name = *dplr*
+- style\\_name = _dplr_
+- style_name = _dplr_
+
+=====================================output=====================================
+- style\\_name = _dplr_
+- style\\_name = _dplr_
+- style_name = _dplr_
+
+================================================================================
+`;
+
+exports[`issue-17286.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+Note: With {"NO\\_PROPAGATE"}, the client is expected to honour the {"errors"} in
+the _response_ and prevent developers from reading a \`null\` produced by an
+
+=====================================output=====================================
+Note: With {"NO\\_PROPAGATE"}, the client is expected to honour the {"errors"} in
+the _response_ and prevent developers from reading a \`null\` produced by an
+
+================================================================================
+`;
+
exports[`nbsp.md - {"proseWrap":"always"} format 1`] = `
====================================options=====================================
parsers: ["markdown"]
diff --git a/tests/format/markdown/emphasis/issue-15032.md b/tests/format/markdown/emphasis/issue-15032.md
new file mode 100644
index 000000000..811f2d71a
--- /dev/null
+++ b/tests/format/markdown/emphasis/issue-15032.md
@@ -0,0 +1,7 @@
+1: The **exponentiation (`**`)** operator.
+
+2: The *exponentiation (`*`)* operator.
+
+3: The _exponentiation (`_`)_ operator.
+
+4: The __exponentiation (`__`)__ operator.
diff --git a/tests/format/markdown/emphasis/issue-16160.md b/tests/format/markdown/emphasis/issue-16160.md
new file mode 100644
index 000000000..29c42da05
--- /dev/null
+++ b/tests/format/markdown/emphasis/issue-16160.md
@@ -0,0 +1,3 @@
+- style\_name = *dplr*
+- style\_name = _dplr_
+- style_name = _dplr_
diff --git a/tests/format/markdown/emphasis/issue-17286.md b/tests/format/markdown/emphasis/issue-17286.md
new file mode 100644
index 000000000..83b7d2942
--- /dev/null
+++ b/tests/format/markdown/emphasis/issue-17286.md
@@ -0,0 +1,2 @@
+Note: With {"NO\_PROPAGATE"}, the client is expected to honour the {"errors"} in
+the _response_ and prevent developers from reading a `null` produced by an
diff --git a/tests/format/markdown/emphasis/issue-3837.md b/tests/format/markdown/emphasis/issue-3837.md
new file mode 100644
index 000000000..b8a849a29
--- /dev/null
+++ b/tests/format/markdown/emphasis/issue-3837.md
@@ -0,0 +1,2 @@
+5 * 10
+a * b * c
diff --git a/tests/format/markdown/emphasis/issue-6112.md b/tests/format/markdown/emphasis/issue-6112.md
new file mode 100644
index 000000000..7649bcf51
--- /dev/null
+++ b/tests/format/markdown/emphasis/issue-6112.md
@@ -0,0 +1,5 @@
+*[Italic link](../_link_including_underscores_.md)*
+
+---
+
+_[Italic link](../_link_including_underscores_.md)_
diff --git a/tests/format/markdown/fenced-code-block/__snapshots__/format.test.js.snap b/tests/format/markdown/fenced-code-block/__snapshots__/format.test.js.snap
index 20b38283f..9eeef0107 100644
--- a/tests/format/markdown/fenced-code-block/__snapshots__/format.test.js.snap
+++ b/tests/format/markdown/fenced-code-block/__snapshots__/format.test.js.snap
@@ -1,5 +1,46 @@
// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+exports[`issue-17300.md format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+ printWidth: 80 (default) |
+=====================================input======================================
+> [NOTE]
+> [Link](https://example.com) after link reference.
+>
+> [IMPORTANT]
+> **Strong emphasis** after link reference.
+
+> [CRITICAL]
+> _emphasis_ oafter link reference
+
+> **Strong emphasis**
+> _emphasis_
+
+[NOTE]: /note
+[IMPORTANT]: /important
+[CRITICAL]: /critical
+
+=====================================output=====================================
+> [NOTE]
+> [Link](https://example.com) after link reference.
+>
+> [IMPORTANT]
+> **Strong emphasis** after link reference.
+
+> [CRITICAL]
+> _emphasis_ oafter link reference
+
+> **Strong emphasis**
+> _emphasis_
+
+[NOTE]: /note
+[IMPORTANT]: /important
+[CRITICAL]: /critical
+
+================================================================================
+`;
+
exports[`snippet: #0 format 1`] = `
====================================options=====================================
parsers: ["markdown"]
diff --git a/tests/format/markdown/fenced-code-block/issue-17300.md b/tests/format/markdown/fenced-code-block/issue-17300.md
new file mode 100644
index 000000000..43a658734
--- /dev/null
+++ b/tests/format/markdown/fenced-code-block/issue-17300.md
@@ -0,0 +1,15 @@
+> [NOTE]
+> [Link](https://example.com) after link reference.
+>
+> [IMPORTANT]
+> **Strong emphasis** after link reference.
+
+> [CRITICAL]
+> _emphasis_ oafter link reference
+
+> **Strong emphasis**
+> _emphasis_
+
+[NOTE]: /note
+[IMPORTANT]: /important
+[CRITICAL]: /critical
diff --git a/tests/format/markdown/list/issue-19146/__snapshots__/format.test.js.snap b/tests/format/markdown/link/parser-regression/__snapshots__/format.test.js.snap
similarity index 77%
rename from tests/format/markdown/list/issue-19146/__snapshots__/format.test.js.snap
rename to tests/format/markdown/link/parser-regression/__snapshots__/format.test.js.snap
index ed6f59d62..c49826470 100644
--- a/tests/format/markdown/list/issue-19146/__snapshots__/format.test.js.snap
+++ b/tests/format/markdown/link/parser-regression/__snapshots__/format.test.js.snap
@@ -1,19 +1,15 @@
// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
-exports[`issue-19146.md - {"proseWrap":"always"} format 1`] = `
+exports[`issue-6078.md - {"proseWrap":"always"} format 1`] = `
====================================options=====================================
parsers: ["markdown"]
proseWrap: "always"
printWidth: 80 (default) |
=====================================input======================================
- - foo
- - bar
- - baz
+[](http://example.com/path?a=1&b=2&c=3)
=====================================output=====================================
-- foo
- - bar
- - baz
+[](http://example.com/path?a=1&b=2&c=3)
================================================================================
`;
diff --git a/tests/format/markdown/list/issue-19146/format.test.js b/tests/format/markdown/link/parser-regression/format.test.js
similarity index 100%
rename from tests/format/markdown/list/issue-19146/format.test.js
rename to tests/format/markdown/link/parser-regression/format.test.js
diff --git a/tests/format/markdown/link/parser-regression/issue-6078.md b/tests/format/markdown/link/parser-regression/issue-6078.md
new file mode 100644
index 000000000..910494a48
--- /dev/null
+++ b/tests/format/markdown/link/parser-regression/issue-6078.md
@@ -0,0 +1 @@
+[](http://example.com/path?a=1&b=2&c=3)
diff --git a/tests/format/markdown/list/parser-regression/__snapshots__/format.test.js.snap b/tests/format/markdown/list/parser-regression/__snapshots__/format.test.js.snap
new file mode 100644
index 000000000..ff12ac2aa
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/__snapshots__/format.test.js.snap
@@ -0,0 +1,190 @@
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+
+exports[`issue-7474.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+1. - XXX
+ - XXX
+2. XXX
+
+=====================================output=====================================
+1. - XXX
+ - XXX
+2. XXX
+
+================================================================================
+`;
+
+exports[`issue-10063.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+# Example 1 (compact list with code block)
+
+- Sibling item before
+- A bullet point with bare text (not in a \`\`), followed by a code block that includes an empty line
+ \`\`\`javascript
+ const foo = "bar";
+
+ console.log(foo);
+ \`\`\`
+- Sibling item after
+
+# Example 2 (compact nested list with code block)
+
+- Parent bullet point which is not wrapped in \`
\`
+ - Sibling item before
+ - Item containing a code block that includes an empty line
+ \`\`\`javascript
+ const foo = "bar";
+
+ console.log(foo);
+ \`\`\`
+ - Sibling item after
+
+# Example 3 (like example 2, but doesn't trigger the bug)
+
+- It works as expected
+ - If the code block
+ - Does not have a line break
+ \`\`\`javascript
+ const foo = "bar";
+ console.log(foo);
+ \`\`\`
+ - It doesn't affect other items
+
+=====================================output=====================================
+# Example 1 (compact list with code block)
+
+- Sibling item before
+- A bullet point with bare text (not in a \`
\`), followed by a code block that
+ includes an empty line
+ \`\`\`javascript
+ const foo = "bar";
+
+ console.log(foo);
+ \`\`\`
+- Sibling item after
+
+# Example 2 (compact nested list with code block)
+
+- Parent bullet point which is not wrapped in \`
\`
+ - Sibling item before
+ - Item containing a code block that includes an empty line
+ \`\`\`javascript
+ const foo = "bar";
+
+ console.log(foo);
+ \`\`\`
+ - Sibling item after
+
+# Example 3 (like example 2, but doesn't trigger the bug)
+
+- It works as expected
+ - If the code block
+ - Does not have a line break
+ \`\`\`javascript
+ const foo = "bar";
+ console.log(foo);
+ \`\`\`
+ - It doesn't affect other items
+
+================================================================================
+`;
+
+exports[`issue-11202.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+\`\`\`markdown
+
+
+-
+-
+-
+\`\`\`
+
+
+=====================================output=====================================
+\`\`\`markdown
+
+
+
+-
+-
+-
+\`\`\`
+
+================================================================================
+`;
+
+exports[`issue-12677.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+5.1 **Section 1**
+
+- apple
+- banana
+- cherry
+
+5.2 **Section 2**
+
+Why is this section indented?
+
+=====================================output=====================================
+5.1 **Section 1**
+
+- apple
+- banana
+- cherry
+
+5.2 **Section 2**
+
+Why is this section indented?
+
+================================================================================
+`;
+
+exports[`issue-19146.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+ - foo
+ - bar
+ - baz
+
+=====================================output=====================================
+- foo
+ - bar
+ - baz
+
+================================================================================
+`;
+
+exports[`issue-19152.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+proseWrap: "always"
+ printWidth: 80 (default) |
+=====================================input======================================
+- foo
+- foo
+
+=====================================output=====================================
+- foo
+- foo
+
+================================================================================
+`;
diff --git a/tests/format/markdown/list/parser-regression/format.test.js b/tests/format/markdown/list/parser-regression/format.test.js
new file mode 100644
index 000000000..6ecc0af19
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/format.test.js
@@ -0,0 +1 @@
+runFormatTest(import.meta, ["markdown"], { proseWrap: "always" });
diff --git a/tests/format/markdown/list/parser-regression/issue-10063.md b/tests/format/markdown/list/parser-regression/issue-10063.md
new file mode 100644
index 000000000..d4811a231
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/issue-10063.md
@@ -0,0 +1,33 @@
+# Example 1 (compact list with code block)
+
+- Sibling item before
+- A bullet point with bare text (not in a `
`), followed by a code block that includes an empty line
+ ```javascript
+ const foo = "bar";
+
+ console.log(foo);
+ ```
+- Sibling item after
+
+# Example 2 (compact nested list with code block)
+
+- Parent bullet point which is not wrapped in `
`
+ - Sibling item before
+ - Item containing a code block that includes an empty line
+ ```javascript
+ const foo = "bar";
+
+ console.log(foo);
+ ```
+ - Sibling item after
+
+# Example 3 (like example 2, but doesn't trigger the bug)
+
+- It works as expected
+ - If the code block
+ - Does not have a line break
+ ```javascript
+ const foo = "bar";
+ console.log(foo);
+ ```
+ - It doesn't affect other items
diff --git a/tests/format/markdown/list/parser-regression/issue-11202.md b/tests/format/markdown/list/parser-regression/issue-11202.md
new file mode 100644
index 000000000..d32b55134
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/issue-11202.md
@@ -0,0 +1,8 @@
+```markdown
+
+
+-
+-
+-
+```
+
diff --git a/tests/format/markdown/list/parser-regression/issue-12677.md b/tests/format/markdown/list/parser-regression/issue-12677.md
new file mode 100644
index 000000000..afb3583cb
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/issue-12677.md
@@ -0,0 +1,9 @@
+5.1 **Section 1**
+
+- apple
+- banana
+- cherry
+
+5.2 **Section 2**
+
+Why is this section indented?
diff --git a/tests/format/markdown/list/issue-19146/issue-19146.md b/tests/format/markdown/list/parser-regression/issue-19146.md
similarity index 100%
rename from tests/format/markdown/list/issue-19146/issue-19146.md
rename to tests/format/markdown/list/parser-regression/issue-19146.md
diff --git a/tests/format/markdown/list/parser-regression/issue-19152.md b/tests/format/markdown/list/parser-regression/issue-19152.md
new file mode 100644
index 000000000..6aec61c00
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/issue-19152.md
@@ -0,0 +1,2 @@
+- foo
+- foo
diff --git a/tests/format/markdown/list/parser-regression/issue-7474.md b/tests/format/markdown/list/parser-regression/issue-7474.md
new file mode 100644
index 000000000..fd20fd78f
--- /dev/null
+++ b/tests/format/markdown/list/parser-regression/issue-7474.md
@@ -0,0 +1,3 @@
+1. - XXX
+ - XXX
+2. XXX
diff --git a/tests/format/markdown/math/__snapshots__/format.test.js.snap b/tests/format/markdown/math/__snapshots__/format.test.js.snap
index 734bbe116..291f12842 100644
--- a/tests/format/markdown/math/__snapshots__/format.test.js.snap
+++ b/tests/format/markdown/math/__snapshots__/format.test.js.snap
@@ -40,6 +40,32 @@ $$
================================================================================
`;
+exports[`issue-12793.md format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+ printWidth: 80 (default) |
+=====================================input======================================
+$ P\\Big(\\mathop{\\cup}\\limits^n_{i=1}A_i\\Big) = \\sum\\limits^n_{i=1}P(A_i) $
+
+=====================================output=====================================
+$ P\\Big(\\mathop{\\cup}\\limits^n_{i=1}A_i\\Big) = \\sum\\limits^n_{i=1}P(A_i) $
+
+================================================================================
+`;
+
+exports[`issue-16664.md format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+ printWidth: 80 (default) |
+=====================================input======================================
+$$ \\textrm{p-value} = 1 - \\sum_{x \\leq a} H(x | N, r_1, m_1) $$
+
+=====================================output=====================================
+$$ \\textrm{p-value} = 1 - \\sum_{x \\leq a} H(x | N, r_1, m_1) $$
+
+================================================================================
+`;
+
exports[`math-like.md format 1`] = `
====================================options=====================================
parsers: ["markdown"]
diff --git a/tests/format/markdown/math/issue-12793.md b/tests/format/markdown/math/issue-12793.md
new file mode 100644
index 000000000..5c1c21e20
--- /dev/null
+++ b/tests/format/markdown/math/issue-12793.md
@@ -0,0 +1 @@
+$ P\Big(\mathop{\cup}\limits^n_{i=1}A_i\Big) = \sum\limits^n_{i=1}P(A_i) $
diff --git a/tests/format/markdown/math/issue-16664.md b/tests/format/markdown/math/issue-16664.md
new file mode 100644
index 000000000..5134ff275
--- /dev/null
+++ b/tests/format/markdown/math/issue-16664.md
@@ -0,0 +1 @@
+$$ \textrm{p-value} = 1 - \sum_{x \leq a} H(x | N, r_1, m_1) $$