docs(formatter_markdown): record unclosed fences closing at a directive's closer (#27279)

crates/oxc_formatter_markdown/DIVERGENCES.md

@@ -301,6 +301,9 @@ Prettier has no directive construct (#19662 would add micromark's grammar only),
 An opener interrupts a paragraph (as in micromark's directive extension and markdown-it-container),
 so like any block it is printed after a blank line, under `preserve` too; Prettier keeps it on the paragraph's next line.
 
+A fence left open inside a directive closes at the directive's closer (as in micromark's directive extension and markdown-it-container),
+so the closing fence is printed explicitly: a reader without directives (CommonMark, GitHub) reads the open fence on to the next closing run, and sees the output's tree change.
+
 ## line-shapes
 
 - Why: semantics

crates/oxc_formatter_markdown/tests/fixtures/markdown/prose-wrap/container-directive.md

@@ -24,3 +24,10 @@ A paragraph right before an opener:
 :::note
 The opener interrupts it, so a blank line separates them.
 :::
+
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+````js
+a
+:::

crates/oxc_formatter_markdown/tests/fixtures/markdown/prose-wrap/container-directive.md.snap

@@ -29,6 +29,13 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+````js
+a
+:::
+
 ==================== Output ====================
 ---------------------------------------
 { printWidth: 80, proseWrap: "always" }
@@ -61,6 +68,14 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 ----------------------------------------
 { printWidth: 100, proseWrap: "always" }
 ----------------------------------------
@@ -90,6 +105,14 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 --------------------------------------
 { printWidth: 80, proseWrap: "never" }
 --------------------------------------
@@ -119,6 +142,14 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 ---------------------------------------
 { printWidth: 100, proseWrap: "never" }
 ---------------------------------------
@@ -148,6 +179,14 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 -----------------------------------------
 { printWidth: 80, proseWrap: "preserve" }
 -----------------------------------------
@@ -179,6 +218,14 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 ------------------------------------------
 { printWidth: 100, proseWrap: "preserve" }
 ------------------------------------------
@@ -210,4 +257,12 @@ A paragraph right before an opener:
 The opener interrupts it, so a blank line separates them.
 :::
 
+<!-- A fence left open inside a directive closes at its closer, printed explicitly -->
+
+::: code-group
+```js
+a
+```
+:::
+
 ===================== End =====================