From 3dbdcdba074f020f88bd4d1f5554d49549973ccd Mon Sep 17 00:00:00 2001
From: Shin'ya Ueoka <ueokande@i-beam.org>
Date: Mon, 8 Jan 2018 18:37:29 +0900
Subject: [PATCH] property parser

---
 src/shared/commands/properties.js     | 31 ++++++++++++++++++++
 test/shared/commands/property.test.js | 41 +++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 src/shared/commands/properties.js
 create mode 100644 test/shared/commands/property.test.js

diff --git a/src/shared/commands/properties.js b/src/shared/commands/properties.js
new file mode 100644
index 0000000..8a3213d
--- /dev/null
+++ b/src/shared/commands/properties.js
@@ -0,0 +1,31 @@
+const mustNumber = (v) => {
+  let num = Number(v);
+  if (isNaN(num)) {
+    throw new Error('Not number: ' + v);
+  }
+  return num;
+};
+
+const parseProperty = (word, types) => {
+  let [key, value] = word.split('=');
+  if (!value) {
+    value = !key.startsWith('no');
+    key = value ? key : key.slice(2);
+  }
+  let type = types[key];
+  if (!type) {
+    throw new Error('Unknown property: ' + key);
+  }
+  if (type === 'boolean' && typeof value !== 'boolean' ||
+       type !== 'boolean' && typeof value === 'boolean') {
+    throw new Error('Invalid argument: ' + word);
+  }
+
+  switch (type) {
+  case 'string': return [key, value];
+  case 'number': return [key, mustNumber(value)];
+  case 'boolean': return [key, value];
+  }
+};
+
+export { parseProperty };
diff --git a/test/shared/commands/property.test.js b/test/shared/commands/property.test.js
new file mode 100644
index 0000000..d949482
--- /dev/null
+++ b/test/shared/commands/property.test.js
@@ -0,0 +1,41 @@
+import { expect } from "chai";
+import { parseProperty } from 'shared/commands/properties';
+
+describe("shared/commands/properties", () => {
+  describe("#parseProperty", () => {
+    it('parse set string', () => {
+      let [key, value] = parseProperty('encoding=utf-8', { encoding: 'string' });
+      expect(key).to.equal('encoding');
+      expect(value).to.equal('utf-8');
+    });
+
+    it('parse set string', () => {
+      let [key, value] = parseProperty('history=50', { history: 'number' });
+      expect(key).to.equal('history');
+      expect(value).to.equal(50);
+    });
+
+    it('parse set boolean', () => {
+      let [key, value] = parseProperty('paste', { paste: 'boolean' });
+      expect(key).to.equal('paste');
+      expect(value).to.be.true;
+
+      [key, value] = parseProperty('nopaste', { paste: 'boolean' });
+      expect(key).to.equal('paste');
+      expect(value).to.be.false;
+    });
+
+    it('throws error on unknown property', () => {
+      expect(() => parseProperty('charset=utf-8', {})).to.throw(Error, 'Unknown');
+      expect(() => parseProperty('smoothscroll', {})).to.throw(Error, 'Unknown');
+      expect(() => parseProperty('nosmoothscroll', {})).to.throw(Error, 'Unknown');
+    })
+
+    it('throws error on invalid property', () => {
+      expect(() => parseProperty('charset=utf-8', { charset: 'number' })).to.throw(Error, 'Not number');
+      expect(() => parseProperty('charset=utf-8', { charset: 'boolean' })).to.throw(Error, 'Invalid');
+      expect(() => parseProperty('smoothscroll', { smoothscroll: 'string' })).to.throw(Error, 'Invalid');
+      expect(() => parseProperty('smoothscroll', { smoothscroll: 'number' })).to.throw(Error, 'Invalid');
+    })
+  });
+});