feat(markdown): support single line code import syntax (close #1355)

Author: meteorlxy

packages/markdown/src/plugins/importCodePlugin/createImportCodeBlockRule.ts

@@ -10,7 +10,14 @@ const MIN_LENGTH = 9
 const START_CODES = [64, 91, 99, 111, 100, 101]
 
 // regexp to match the import syntax
-const SYNTAX_RE = /^@\[code(?:{(?:(\d+)?-(\d+)?)})?(?: ([^\]]+))?\]\(([^)]*)\)/
+const SYNTAX_RE =
+  /^@\[code(?:{(?:(?:(?<lineStart>\d+)?-(?<lineEnd>\d+)?)|(?<lineSingle>\d+))})?(?: (?<info>[^\]]+))?\]\((?<importPath>[^)]*)\)/
+
+/**
+ * Utility function to parse line number from line string that matched by SYNTAX_RE
+ */
+const parseLineNumber = (line: string | undefined): number | undefined =>
+  line ? Number.parseInt(line, 10) : undefined
 
 export const createImportCodeBlockRule =
   ({ handleImportPath = (str) => str }: ImportCodePluginOptions): RuleBlock =>
@@ -36,17 +43,21 @@ export const createImportCodeBlockRule =
 
     // check if it's matched the syntax
     const match = state.src.slice(pos, max).match(SYNTAX_RE)
-    if (!match) return false
+    if (!match?.groups) return false
 
     // return true as we have matched the syntax
     if (silent) return true
 
-    const [, lineStart, lineEnd, info, importPath] = match
+    const { info, importPath } = match.groups
+
+    const lineSingle = parseLineNumber(match.groups.lineSingle)
+    const lineStart = lineSingle ?? parseLineNumber(match.groups.lineStart) ?? 0
+    const lineEnd = lineSingle ?? parseLineNumber(match.groups.lineEnd)
 
     const meta: ImportCodeTokenMeta = {
       importPath: handleImportPath(importPath),
-      lineStart: lineStart ? Number.parseInt(lineStart, 10) : 0,
-      lineEnd: lineEnd ? Number.parseInt(lineEnd, 10) : undefined,
+      lineStart,
+      lineEnd,
     }
 
     // create a import_code token

packages/markdown/tests/plugins/importCodePlugin.spec.ts

@@ -87,8 +87,10 @@ ${mdFixtureContent}\
       const source = `\
 @[code{1-2}](${jsFixturePathRelative})
 @[code{1-}](${jsFixturePathRelative})
+@[code{2}](${jsFixturePathRelative})
 @[code{4-5}](${mdFixturePathRelative})
 @[code{-5}](${mdFixturePathRelative})
+@[code{5}](${mdFixturePathRelative})
 `
 
       const expected = `\
@@ -98,12 +100,18 @@ ${jsFixtureContent.split('\n').slice(0, 2).join('\n').replace(/\n?$/, '\n')}\
 <pre><code class="language-js">\
 ${jsFixtureContent.split('\n').slice(0).join('\n').replace(/\n?$/, '\n')}\
 </code></pre>
+<pre><code class="language-js">\
+${jsFixtureContent.split('\n').slice(1, 1).join('\n').replace(/\n?$/, '\n')}\
+</code></pre>
 <pre><code class="language-md">\
 ${mdFixtureContent.split('\n').slice(3, 5).join('\n').replace(/\n?$/, '\n')}\
 </code></pre>
 <pre><code class="language-md">\
 ${mdFixtureContent.split('\n').slice(0, 5).join('\n').replace(/\n?$/, '\n')}\
 </code></pre>
+<pre><code class="language-md">\
+${mdFixtureContent.split('\n').slice(4, 5).join('\n').replace(/\n?$/, '\n')}\
+</code></pre>
 `
 
       const md = MarkdownIt().use(importCodePlugin)
@@ -116,6 +124,8 @@ ${mdFixtureContent.split('\n').slice(0, 5).join('\n').replace(/\n?$/, '\n')}\
       expect(env.importedFiles).toEqual([
         jsFixturePath,
         jsFixturePath,
+        jsFixturePath,
+        mdFixturePath,
         mdFixturePath,
         mdFixturePath,
       ])