yeonjuan · yeonjuan · Nov 20, 2023 · Nov 19, 2023
diff --git a/docs/rules/require-open-graph-protocol.md b/docs/rules/require-open-graph-protocol.md
@@ -0,0 +1,66 @@
+---
+id: require-open-graph-protocol
+title: "require-open-graph-protocol"
+---
+
+# require-open-graph-protocol
+
+Enforce to use specified meta tags for open graph protocol.
+
+## How to use
+
+.eslintrc.js
+
+```js
+module.exports = {
+  rules: {
+    "@html-eslint/require-open-graph-protocol": "error",
+  },
+};
+```
+
+## Rule Details
+
+### Options
+
+- `ogp` (default: ['og:title', 'og:type', 'og:url', 'og:image']): enforce to use specified open graph protocol meta tags
+
+Examples of **incorrect** code for this rule with the default `{ "ogp": ['og:title', 'og:type', 'og:url', 'og:image'] }` options:
+
+```html
+<html>
+  <head>
+    <title>title</title>
+  </head>
+</html>
+```
+
+<!-- prettier-ignore -->
+```html
+<html>
+  <head>
+    <title>title</title>
+    <!-- empty values -->
+    <meta property="og:url" />
+    <meta property="og:image" content="" /> 
+  </head>
+</html>
+```
+
+Examples of **correct** code for this rule:
+
+```html
+<html>
+  <head>
+    <title>title</title>
+    <meta property="og:url" content="https://canonical-url.com" />
+    <meta property="og:type" content="video.movie" />
+    <meta property="og:title" content="title" />
+    <meta property="og:image" content="https://image.png" />
+  </head>
+</html>
+```
+
+## Further reading
+
+- [The Open Graph protocol](https://ogp.me/)
diff --git a/packages/eslint-plugin/lib/rules/index.js b/packages/eslint-plugin/lib/rules/index.js
@@ -33,6 +33,7 @@ const requireAttrs = require("./require-attrs");
 const noRestrictedAttrValues = require("./no-restricted-attr-values");
 const noScriptStyleType = require("./no-script-style-type");
 const lowercase = require("./lowercase");
+const requireOpenGraphProtocol = require("./require-open-graph-protocol");
 
 module.exports = {
   "require-lang": requireLang,
@@ -70,4 +71,5 @@ module.exports = {
   "no-restricted-attr-values": noRestrictedAttrValues,
   "no-script-style-type": noScriptStyleType,
   lowercase: lowercase,
+  "require-open-graph-protocol": requireOpenGraphProtocol,
 };
diff --git a/packages/eslint-plugin/lib/rules/require-open-graph-protocol.js b/packages/eslint-plugin/lib/rules/require-open-graph-protocol.js
@@ -0,0 +1,135 @@
+const { NODE_TYPES } = require("@html-eslint/parser");
+const { RULE_CATEGORY } = require("../constants");
+const { filter } = require("./utils/array");
+const { findAttr } = require("./utils/node");
+
+const MESSAGE_IDS = {
+  MISSING: "missing",
+  EMPTY: "empty",
+};
+
+const DEFAULT_REQUIRED_PROPERTIES = [
+  "og:title",
+  "og:type",
+  "og:url",
+  "og:image",
+];
+
+/**
+ * @param {string[]} properties
+ * @returns {string[]}
+ */
+function normalize(properties) {
+  return properties.map((prop) => {
+    if (prop.indexOf("og:") === 0) return prop;
+    return `og:${prop}`;
+  });
+}
+
+/**
+ * @type {Rule}
+ */
+module.exports = {
+  meta: {
+    type: "code",
+
+    docs: {
+      description: 'Enforce to use `<meta name="viewport">` in `<head>`',
+      category: RULE_CATEGORY.SEO,
+      recommended: false,
+    },
+
+    fixable: null,
+    schema: [
+      {
+        type: "array",
+        items: {
+          type: "string",
+        },
+        uniqueItems: true,
+      },
+    ],
+    messages: {
+      [MESSAGE_IDS.MISSING]:
+        "Require use of meta tags for OGP. ({{properties}})",
+      [MESSAGE_IDS.EMPTY]: "Unexpected empty 'content' attribute",
+    },
+  },
+
+  create(context) {
+    /**
+     * @type {string[]}
+     */
+    const requiredProperties = normalize(
+      (context.options && context.options[0]) || DEFAULT_REQUIRED_PROPERTIES
+    );
+
+    /**
+     * @param {ChildType<TagNode>} node
+     * @returns {node is TagNode}
+     */
+    function isOgpMeta(node) {
+      const isMeta = node.type === NODE_TYPES.Tag && node.name === "meta";
+      const property = isMeta ? findAttr(node, "property") : undefined;
+      const hasOgProperty =
+        !!property &&
+        !!property.value &&
+        property.value.value.indexOf("og:") === 0;
+      return hasOgProperty;
+    }
+
+    return {
+      Tag(node) {
+        if (node.name !== "head") {
+          return;
+        }
+        const children = node.children;
+
+        const metaTags = filter(children, isOgpMeta);
+
+        const missingProperties = requiredProperties.filter((required) => {
+          return !metaTags.some((meta) => {
+            const property = findAttr(meta, "property");
+            if (property && property.value) {
+              return property.value.value === required;
+            }
+            return false;
+          });
+        });
+
+        const emptyContentMetaTags = metaTags.filter((meta) => {
+          const property = findAttr(meta, "property");
+          if (
+            property &&
+            property.value &&
+            requiredProperties.includes(property.value.value)
+          ) {
+            const content = findAttr(meta, "content");
+            return !content || !content.value || !content.value.value;
+          }
+          return false;
+        });
+
+        if (missingProperties.length) {
+          context.report({
+            node,
+            data: {
+              properties: missingProperties.join(", "),
+            },
+            messageId: MESSAGE_IDS.MISSING,
+          });
+        }
+
+        if (emptyContentMetaTags.length) {
+          emptyContentMetaTags.forEach((meta) => {
+            const content = findAttr(meta, "content");
+            context.report({
+              node: content || meta,
+              messageId: MESSAGE_IDS.EMPTY,
+            });
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/packages/eslint-plugin/lib/rules/utils/node.js b/packages/eslint-plugin/lib/rules/utils/node.js
@@ -1,10 +1,3 @@
-/**
- * @typedef {import("es-html-parser").TagNode} TagNode
- * @typedef {import("es-html-parser").AnyNode} AnyNode
- * @typedef {import("es-html-parser").TextNode} TextNode
- * @typedef {import("es-html-parser").AttributeNode} AttributeNode
- */
-
 module.exports = {
   /**
    * @param {TagNode | ScriptTagNode | StyleTagNode} node

diff --git a/packages/eslint-plugin/lib/types.d.ts b/packages/eslint-plugin/lib/types.d.ts
@@ -1,8 +1,6 @@
 import ESTree from "estree";
 import ESLint from "eslint";
 import * as ESHtml from "es-html-parser";
-{
-}
 
 declare global {
   type Fix = ESLint.Rule.Fix;
@@ -59,6 +57,8 @@ declare global {
   }
 
   interface AttributeNode extends ESHtml.AttributeNode {
+    key: AttributeKeyNode;
+    value?: AttributeValueNode;
     parent: TagNode | StyleTagNode | ScriptTagNode;
   }
 

diff --git a/packages/eslint-plugin/tests/rules/require-open-graph-protocol.test.js b/packages/eslint-plugin/tests/rules/require-open-graph-protocol.test.js
@@ -0,0 +1,125 @@
+const createRuleTester = require("../rule-tester");
+const rule = require("../../lib/rules/require-open-graph-protocol");
+
+const ruleTester = createRuleTester();
+
+ruleTester.run("require-open-graph-protocol", rule, {
+  valid: [
+    {
+      code: "<html></html>",
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:url" content="title" />
+        <meta property="og:type" content="video.movie" />
+        <meta property="og:title" content="title" />
+        <meta property="og:image" content="https://image.png" />
+      </head>
+      </html>`,
+    },
+  ],
+  invalid: [
+    {
+      code: "<html><head></head></html>",
+      errors: [
+        {
+          message:
+            "Require use of meta tags for OGP. (og:title, og:type, og:url, og:image)",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:title" content="title">
+      </head>
+      </html>`,
+      errors: [
+        {
+          message:
+            "Require use of meta tags for OGP. (og:type, og:url, og:image)",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:title" content="title" />
+        <meta property="og:image" content="https://image.png" />
+      </head>
+      </html>`,
+      errors: [
+        {
+          message: "Require use of meta tags for OGP. (og:type, og:url)",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:title" content="title" />
+        <meta property="og:image" content="https://image.png" />
+      </head>
+      </html>`,
+      options: [["description"]],
+      errors: [
+        {
+          message: "Require use of meta tags for OGP. (og:description)",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:title" content="title" />
+        <meta property="og:image" content="https://image.png" />
+      </head>
+      </html>`,
+      options: [["og:description", "og:video"]],
+      errors: [
+        {
+          message:
+            "Require use of meta tags for OGP. (og:description, og:video)",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:url" content="title" />
+        <meta property="og:type" content="video.movie" />
+        <meta property="og:title" content="" />
+        <meta property="og:image" />
+      </head>
+      </html>`,
+      errors: [
+        {
+          messageId: "empty",
+        },
+        {
+          messageId: "empty",
+        },
+      ],
+    },
+    {
+      code: `<html>
+      <head>
+        <meta property="og:url" />
+        <meta property="og:type" content="video.movie" />
+        <meta property="og:title" content="" />
+        <meta property="og:image" />
+      </head>
+      </html>`,
+      options: [["title", "og:image"]],
+      errors: [
+        {
+          messageId: "empty",
+        },
+        {
+          messageId: "empty",
+        },
+      ],
+    },
+  ],
+});