Chore: add internal rule to enforce meta.docs conventions (fixes #6954)

docs/rules/sort-keys.md

@@ -1,4 +1,4 @@
-# requires object keys to be sorted (sort-keys)
+# require object keys to be sorted (sort-keys)
 
 When declaring multiple properties, some developers prefer to sort property names alphabetically to be able to find necessary property easier at the later time. Others feel that it adds complexity and becomes burden to maintain.
 

lib/internal-rules/.eslintrc.yml

@@ -0,0 +1,3 @@
+rules:
+    internal-no-invalid-meta: "error"
+    internal-consistent-docs-description: "error"

lib/internal-rules/internal-consistent-docs-description.js

@@ -0,0 +1,131 @@
+/**
+ * @fileoverview Internal rule to enforce meta.docs.description conventions.
+ * @author Vitor Balocco
+ */
+
+"use strict";
+
+const ALLOWED_FIRST_WORDS = [
+    "enforce",
+    "require",
+    "disallow"
+];
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Gets the property of the Object node passed in that has the name specified.
+ *
+ * @param {string} property Name of the property to return.
+ * @param {ASTNode} node The ObjectExpression node.
+ * @returns {ASTNode} The Property node or null if not found.
+ */
+function getPropertyFromObject(property, node) {
+    const properties = node.properties;
+
+    for (let i = 0; i < properties.length; i++) {
+        if (properties[i].key.name === property) {
+            return properties[i];
+        }
+    }
+
+    return null;
+}
+
+/**
+ * Verifies that the meta.docs.description property follows our internal conventions.
+ *
+ * @param {RuleContext} context The ESLint rule context.
+ * @param {ASTNode} exportsNode ObjectExpression node that the rule exports.
+ * @returns {void}
+ */
+function checkMetaDocsDescription(context, exportsNode) {
+    if (exportsNode.type !== "ObjectExpression") {
+
+        // if the exported node is not the correct format, "internal-no-invalid-meta" will already report this.
+        return;
+    }
+
+    const metaProperty = getPropertyFromObject("meta", exportsNode);
+    const metaDocs = metaProperty && getPropertyFromObject("docs", metaProperty.value);
+    const metaDocsDescription = metaDocs && getPropertyFromObject("description", metaDocs.value);
+
+    if (!metaDocsDescription) {
+
+        // if there is no `meta.docs.description` property, "internal-no-invalid-meta" will already report this.
+        return;
+    }
+
+    const description = metaDocsDescription.value.value;
+
+    if (typeof description !== "string") {
+        context.report({
+            node: metaDocsDescription.value,
+            message: "`meta.docs.description` should be a string."
+        });
+        return;
+    }
+
+    if (description === "") {
+        context.report({
+            node: metaDocsDescription.value,
+            message: "`meta.docs.description` should not be empty.",
+        });
+        return;
+    }
+
+    if (description.indexOf(" ") === 0) {
+        context.report({
+            node: metaDocsDescription.value,
+            message: "`meta.docs.description` should not start with whitespace."
+        });
+        return;
+    }
+
+    const firstWord = description.split(" ")[0];
+
+    if (ALLOWED_FIRST_WORDS.indexOf(firstWord) === -1) {
+        context.report({
+            node: metaDocsDescription.value,
+            message: "`meta.docs.description` should start with one of the following words: {{ allowedWords }}. Started with \"{{ firstWord }}\" instead.",
+            data: {
+                allowedWords: ALLOWED_FIRST_WORDS.join(", "),
+                firstWord
+            }
+        });
+        return;
+    }
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce correct conventions of `meta.docs.description` property in core rules",
+            category: "Internal",
+            recommended: false
+        },
+
+        schema: []
+    },
+
+    create(context) {
+        return {
+            AssignmentExpression(node) {
+                if (node.left &&
+                    node.right &&
+                    node.left.type === "MemberExpression" &&
+                    node.left.object.name === "module" &&
+                    node.left.property.name === "exports") {
+
+                    checkMetaDocsDescription(context, node.right);
+                }
+            }
+        };
+    }
+};

lib/rules/.eslintrc.yml

@@ -1,2 +1,3 @@
 rules:
     internal-no-invalid-meta: "error"
+    internal-consistent-docs-description: "error"

lib/rules/sort-keys.js

@@ -1,5 +1,5 @@
 /**
- * @fileoverview Rule to requires object keys to be sorted
+ * @fileoverview Rule to require object keys to be sorted
  * @author Toru Nagashima
  */
 
@@ -74,7 +74,7 @@ const isValidOrders = {
 module.exports = {
     meta: {
         docs: {
-            description: "requires object keys to be sorted",
+            description: "require object keys to be sorted",
             category: "Stylistic Issues",
             recommended: false
         },