1 files changed, 95 insertions, 0 deletions
diff --git a/packages/gitbook/src/fs/mock.js b/packages/gitbook/src/fs/mock.js
new file mode 100644
index 0000000..611b2ab
--- /dev/null
+++ b/packages/gitbook/src/fs/mock.js
@@ -0,0 +1,95 @@
+const path = require('path');
+const is = require('is');
+const Buffer = require('buffer').Buffer;
+const Immutable = require('immutable');
+
+const FS = require('../models/fs');
+const error = require('../utils/error');
+
+/**
+ * Create a fake filesystem for unit testing GitBook.
+ * @param {Map<String:String|Map>}
+ * @return {FS}
+ */
+function createMockFS(files, root = '') {
+    files = Immutable.fromJS(files);
+    const mtime = new Date();
+
+    function getFile(filePath) {
+        const parts = path.normalize(filePath).split(path.sep);
+        return parts.reduce(function(list, part, i) {
+            if (!list) return null;
+
+            let file;
+
+            if (!part || part === '.') file = list;
+            else file = list.get(part);
+
+            if (!file) return null;
+
+            if (is.string(file)) {
+                if (i === (parts.length - 1)) return file;
+                else return null;
+            }
+
+            return file;
+        }, files);
+    }
+
+    function fsExists(filePath) {
+        return Boolean(getFile(filePath) !== null);
+    }
+
+    function fsReadFile(filePath) {
+        const file = getFile(filePath);
+        if (!is.string(file)) {
+            throw error.FileNotFoundError({
+                filename: filePath
+            });
+        }
+
+        return new Buffer(file, 'utf8');
+    }
+
+    function fsStatFile(filePath) {
+        const file = getFile(filePath);
+        if (!file) {
+            throw error.FileNotFoundError({
+                filename: filePath
+            });
+        }
+
+        return {
+            mtime
+        };
+    }
+
+    function fsReadDir(filePath) {
+        const dir = getFile(filePath);
+        if (!dir || is.string(dir)) {
+            throw error.FileNotFoundError({
+                filename: filePath
+            });
+        }
+
+        return dir
+            .map(function(content, name) {
+                if (!is.string(content)) {
+                    name = name + '/';
+                }
+
+                return name;
+            })
+            .valueSeq();
+    }
+
+    return FS.create({
+        root: '',
+        fsExists,
+        fsReadFile,
+        fsStatFile,
+        fsReadDir
+    });
+}
+
+module.exports = createMockFS;