Refactor to move implementation to lib/

index.js

@@ -1,56 +1,5 @@
 /**
- * @typedef {import('mdast').Heading} Heading
- * @typedef {'atx'|'atx-closed'|'setext'} Style
+ * @typedef {import('./lib/index.js').Style} Style
  */
 
-/**
- * @param {Heading} node
- * @param {Style} [relative]
- * @returns {Style|null}
- */
-export function headingStyle(node, relative) {
-  const last = node.children[node.children.length - 1]
-  const depth = node.depth
-  const pos = node && node.position && node.position.end
-  const final = last && last.position && last.position.end
-
-  if (!pos) {
-    return null
-  }
-
-  // This can only occur for `'atx'` and `'atx-closed'` headings.
-  // This might incorrectly match `'atx'` headings with lots of trailing white
-  // space as an `'atx-closed'` heading.
-  if (!last) {
-    if (pos.column - 1 <= depth * 2) {
-      return consolidate(depth, relative)
-    }
-
-    return 'atx-closed'
-  }
-
-  if (final && final.line + 1 === pos.line) {
-    return 'setext'
-  }
-
-  if (final && final.column + depth < pos.column) {
-    return 'atx-closed'
-  }
-
-  return consolidate(depth, relative)
-}
-
-/**
- * Get the probable style of an atx-heading, depending on preferred style.
- *
- * @param {number} depth
- * @param {Style|undefined} relative
- * @returns {Style|null}
- */
-function consolidate(depth, relative) {
-  return depth < 3
-    ? 'atx'
-    : relative === 'atx' || relative === 'setext'
-    ? relative
-    : null
-}
+export {headingStyle} from './lib/index.js'

lib/index.js

@@ -0,0 +1,56 @@
+/**
+ * @typedef {import('mdast').Heading} Heading
+ * @typedef {'atx'|'atx-closed'|'setext'} Style
+ */
+
+/**
+ * @param {Heading} node
+ * @param {Style} [relative]
+ * @returns {Style|null}
+ */
+export function headingStyle(node, relative) {
+  const last = node.children[node.children.length - 1]
+  const depth = node.depth
+  const pos = node && node.position && node.position.end
+  const final = last && last.position && last.position.end
+
+  if (!pos) {
+    return null
+  }
+
+  // This can only occur for `'atx'` and `'atx-closed'` headings.
+  // This might incorrectly match `'atx'` headings with lots of trailing white
+  // space as an `'atx-closed'` heading.
+  if (!last) {
+    if (pos.column - 1 <= depth * 2) {
+      return consolidate(depth, relative)
+    }
+
+    return 'atx-closed'
+  }
+
+  if (final && final.line + 1 === pos.line) {
+    return 'setext'
+  }
+
+  if (final && final.column + depth < pos.column) {
+    return 'atx-closed'
+  }
+
+  return consolidate(depth, relative)
+}
+
+/**
+ * Get the probable style of an atx-heading, depending on preferred style.
+ *
+ * @param {number} depth
+ * @param {Style|undefined} relative
+ * @returns {Style|null}
+ */
+function consolidate(depth, relative) {
+  return depth < 3
+    ? 'atx'
+    : relative === 'atx' || relative === 'setext'
+    ? relative
+    : null
+}

package.json

@@ -29,6 +29,7 @@
   "main": "index.js",
   "types": "index.d.ts",
   "files": [
+    "lib/",
     "index.d.ts",
     "index.js"
   ],