feat: restrictRelativePath option (close #1646)

packages/markdown/src/plugins/assetsPlugin/assetsPlugin.ts

@@ -13,6 +13,17 @@ export interface AssetsPluginOptions {
    * Prefix to add to relative assets links
    */
   relativePathPrefix?: string
+
+  /**
+   * The strictness of the determination of relative paths
+   *
+   * When different options are set, the criteria for identifying relative paths are as follows:
+   *
+   * - true:       start with `./` or `../`
+   * - false:      no start with `/` or `<protocol header>`
+   * - '@-perfix': no start with `/` or `@` or `<protocol header>`
+   */
+  restrictRelativePath?: boolean | '@-perfix'
 }
 
 /**
@@ -23,6 +34,7 @@ export const assetsPlugin: PluginWithOptions<AssetsPluginOptions> = (
   {
     absolutePathPrependBase = false,
     relativePathPrefix = '@source',
+    restrictRelativePath = true,
   }: AssetsPluginOptions = {},
 ) => {
   // wrap raw image renderer rule
@@ -58,7 +70,7 @@ export const assetsPlugin: PluginWithOptions<AssetsPluginOptions> = (
               env,
               absolutePathPrependBase,
               relativePathPrefix,
-              strict: true,
+              strict: restrictRelativePath,
             })}${quote}`,
         )
         // handle srcset
@@ -75,7 +87,7 @@ export const assetsPlugin: PluginWithOptions<AssetsPluginOptions> = (
                       env,
                       absolutePathPrependBase,
                       relativePathPrefix,
-                      strict: true,
+                      strict: restrictRelativePath,
                     })}${descriptor.replace(/[ \n]+/g, ' ').trimEnd()}`,
                 ),
               )

packages/markdown/src/plugins/assetsPlugin/resolveLink.ts

@@ -6,7 +6,7 @@ interface ResolveLinkOptions {
   env: MarkdownEnv
   absolutePathPrependBase?: boolean
   relativePathPrefix: string
-  strict?: boolean
+  strict?: boolean | '@-perfix'
 }
 
 export const resolveLink = (
@@ -25,11 +25,14 @@ export const resolveLink = (
   let resolvedLink = decode(link)
 
   // check if the link is relative path
-  const isRelativePath = strict
-    ? // in strict mode, only link that starts with `./` or `../` is considered as relative path
-      /^\.{1,2}\//.test(link)
-    : // in non-strict mode, link that does not start with `/` and does not have protocol is considered as relative path
-      !link.startsWith('/') && !/[A-z]+:\/\//.test(link)
+  const isRelativePath =
+    strict === true
+      ? /^\.{1,2}\//.test(link)
+      : strict === false
+        ? !link.startsWith('/') && !/[A-z]+:\/\//.test(link)
+        : !link.startsWith('/') &&
+          !link.startsWith('@') &&
+          !/[A-z]+:\/\//.test(link)
 
   // if the link is relative path, and the `env.filePathRelative` exists
   // add `@source` alias to the link