feat: add siteConfig loader

test/loader/__fixtures__/custom/.blogi/config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  title: 'Hello World',
+  description: 'Hello World',
+  dest: 'blogi',
+  base: 'blogi'
+};

test/loader/__fixtures__/custom/hello.md

@@ -0,0 +1,5 @@
+---
+title: Hello, World !
+---
+
+Hello World

test/loader/__fixtures__/simple/.blogi/config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  title: 'Hello World',
+  description: 'Hello World'
+};

test/loader/__fixtures__/simple/hello.md

@@ -0,0 +1,5 @@
+---
+title: Hello, World !
+---
+
+Hello World

test/loader/config.test.js

@@ -0,0 +1,28 @@
+const path = require('path');
+const fs = require('fs');
+const loadConfig = require('../../lib/loader/config');
+
+describe('loadConfig', () => {
+  const simpleDir = path.join(__dirname, '__fixtures__', 'simple');
+  const customDir = path.join(__dirname, '__fixtures__', 'custom');
+
+  test('simple', () => {
+    expect(loadConfig(simpleDir)).toMatchInlineSnapshot(`
+Object {
+  "description": "Hello World",
+  "title": "Hello World",
+}
+`);
+  });
+
+  test('custom', () => {
+    expect(loadConfig(customDir)).toMatchInlineSnapshot(`
+Object {
+  "base": "blogi",
+  "description": "Hello World",
+  "dest": "blogi",
+  "title": "Hello World",
+}
+`);
+  });
+});