fix: dangling anchor links with german umlauts (#27). See updates to …

…doc/vuepress.md and slugify option.

lib/glossarify.js

@@ -6,6 +6,7 @@ const terminator = require("./terminator");
 const linker = require("./linker");
 const writer = require("./writer");
 const Dictionary = require("./dictionary");
+const GitHubSlugger = require("github-slugger");
 
 const api = {};
 const CWD = proc.cwd();
@@ -31,6 +32,26 @@ api.glossarify = function(opts) {
         .catch(err => console.error(err) && proc.exit(1));
 }
 
+/**
+ * Provide internally used slugifier to allow for better integration with vuepress
+ * See also https://github.com/about-code/glossarify-md/issues/27.
+ */
+api.getSlugger = function() {
+    return (url) => {
+        const slugger = new GitHubSlugger();
+        return slugger.slug(url);
+    };
+    // Implementation note:
+    // GitHubSlugger is stateful to be able to create unique names if the same
+    // anchor/headline/term occurs twice on a *single page*. But slugify function
+    // provided to vuepress will be invoked for different pages of a project.
+    // They would appear to GitHubSlugger as being a single page / namespace if
+    // we didn't create a new GitHubSlugger with every call, here. Rather than
+    // creating a new instance we could also close over a single instance and
+    // call 'slugger.reset()'. But, we decided to create an instance in the
+    // function body which can be garbage collected immediately after the call.
+}
+
 /**
  * @private
  * @param {} context

package.json

@@ -44,6 +44,7 @@
   "license": "MIT",
   "dependencies": {
     "fs-extra": "^8.1.0",
+    "github-slugger": "^1.0.0",
     "glob": "^7.0.3",
     "minimist": "^1.2.0",
     "minimist-options": "^4.0.1",