1 files changed, 54 insertions, 0 deletions
diff --git a/packages/gitbook-core/src/models/File.js b/packages/gitbook-core/src/models/File.js
new file mode 100644
index 0000000..efc4f11
--- /dev/null
+++ b/packages/gitbook-core/src/models/File.js
@@ -0,0 +1,54 @@
+const path = require('path');
+const { Record } = require('immutable');
+
+const DEFAULTS = {
+    type:  '',
+    mtime: new Date(),
+    path:  '',
+    url:   ''
+};
+
+class File extends Record(DEFAULTS) {
+    constructor(file = {}) {
+        if (typeof file === 'string') {
+            file = { path: file, url: file };
+        }
+
+        super({
+            ...file,
+            mtime: new Date(file.mtime)
+        });
+    }
+
+    /**
+     * @param {String} to Absolute path
+     * @return {String} The same path, but relative to this file
+     */
+    relative(to) {
+        return path.relative(
+            path.dirname(this.path),
+            to
+        ) || './';
+    }
+
+    /**
+     * Return true if file is an instance of File
+     * @param {Mixed} file
+     * @return {Boolean} isFile
+     */
+    static is(file) {
+        return (file instanceof File);
+    }
+
+    /**
+     * Create a file instance
+     * @param {Mixed|File} file
+     * @return {File} file
+     */
+    static create(file) {
+        return File.is(file) ?
+            file : new File(file);
+    }
+}
+
+module.exports = File;