Add support for "absolute" root syntax

dist/markdownItInclude.mjs

@@ -71,7 +71,7 @@ const include_plugin = (md, options) => {
       }
 
       if (!errorMessage) {
-        filePath = path.resolve(rootdir, includePath); // check if child file exists or if there is a circular reference
+        filePath = path.resolve(includePath.indexOf('/') === 0 ? rootdir : parentFilePath ? path.dirname(parentFilePath) : rootdir, `./${includePath}`); // check if child file exists or if there is a circular reference
 
         if (!fs.existsSync(filePath)) {
           // child file does not exist
@@ -93,7 +93,7 @@ const include_plugin = (md, options) => {
         // get content of child file
         mdSrc = fs.readFileSync(filePath, 'utf8'); // check if child file also has includes
 
-        mdSrc = _replaceIncludeByContent(mdSrc, path.dirname(filePath), filePath, filesProcessed); // remove one trailing newline, if it exists: that way, the included content does NOT
+        mdSrc = _replaceIncludeByContent(mdSrc, rootdir, filePath, filesProcessed); // remove one trailing newline, if it exists: that way, the included content does NOT
         // automatically terminate the paragraph it is in due to the writer of the included
         // part having terminated the content with a newline.
         // However, when that snippet writer terminated with TWO (or more) newlines, these, minus one,

index.js

@@ -51,7 +51,12 @@ const include_plugin = (md, options) => {
       }
 
       if (!errorMessage) {
-        filePath = path.resolve(rootdir, includePath);
+        filePath = path.resolve(includePath.indexOf('/') === 0
+          ? rootdir
+          : parentFilePath
+            ? path.dirname(parentFilePath)
+            : rootdir
+        , `./${includePath}`);
 
         // check if child file exists or if there is a circular reference
         if (!fs.existsSync(filePath)) {
@@ -73,7 +78,7 @@ const include_plugin = (md, options) => {
         // get content of child file
         mdSrc = fs.readFileSync(filePath, 'utf8');
         // check if child file also has includes
-        mdSrc = _replaceIncludeByContent(mdSrc, path.dirname(filePath), filePath, filesProcessed);
+        mdSrc = _replaceIncludeByContent(mdSrc, rootdir, filePath, filesProcessed);
         // remove one trailing newline, if it exists: that way, the included content does NOT
         // automatically terminate the paragraph it is in due to the writer of the included
         // part having terminated the content with a newline.

test/default.js

@@ -27,6 +27,14 @@ describe('plugin', () => {
         '<p><em>a content</em>\n<em>a content</em></p>\n');
     });
 
+    it ('absolute root path reference', () => {
+      const md = markdown()
+        .use(markdown_it_include, fixturesPath);
+
+      assert.equal(md.render('!!! include( L1/L2/r.md ) !!!'),
+        '<p><em>a content</em></p>\n');
+    });
+
     it ('default options', () => {
       let md = markdown()
         .use(markdown_it_include);

test/fixtures/L1/L2/r.md

@@ -0,0 +1 @@
+!!!include(/a.md)!!!