Add utility class to validate TavernCard characters

src/validator/TavernCardValidator.js

@@ -0,0 +1,129 @@
+const characterBook = require("lodash/object");
+
+/**
+ * Validates the data structure of character cards.
+ * Supported specs: V1, V2
+ * Up to: 8083fb3
+ *
+ * @link https://github.com/malfoyslastname/character-card-spec-v2
+ */
+class TavernCardValidator {
+    #validationError = null;
+
+    constructor(card) {
+        this.card = card;
+    }
+
+    /**
+     * Field that caused the validation to fail
+     *
+     * @returns {null|string}
+     */
+    get validationError() {
+        return this.#validationError;
+    }
+
+    /**
+     * Validate against V1 and V2 spec.
+     *
+     * @returns {number|boolean} - false when neither V1 nor V2 spec were matched. Specification version number otherwise.
+     */
+    validate() {
+        this.#validationError = null;
+
+        if (this.validateV1()) {
+            return 2;
+        }
+
+        if (this.validateV2()) {
+            return 1;
+        }
+
+        return false;
+    }
+
+    /**
+     * Validate against V1 specification
+     *
+     * @returns {this is string[]}
+     */
+    validateV1() {
+        const requiredFields = ['name', 'description', 'personality', 'scenario', 'first_mes', 'mes_example'];
+        return requiredFields.every(field => {
+            if (!this.card.hasOwnProperty(field)) {
+                this.#validationError = field;
+                return false;
+            }
+            return true;
+        });
+    }
+
+    /**
+     * Validate against V2 specification
+     *
+     * @returns {false|boolean|*}
+     */
+    validateV2() {
+        return this.#validateSpec()
+            && this.#validateSpecVersion()
+            && this.#validateData()
+            && this.#validateCharacterBook();
+    }
+
+    #validateSpec() {
+        if (this.card.spec !== 'chara_card_v2') {
+            this.#validationError = 'spec';
+            return false;
+        }
+        return true;
+    }
+
+    #validateSpecVersion() {
+        if (this.card.spec_version !== '2.0') {
+            this.#validationError = 'spec_version';
+            return false;
+        }
+        return true;
+    }
+
+    #validateData() {
+        const data = this.card.data;
+
+        if (!data) {
+            this.#validationError = 'data';
+            return false;
+        }
+
+        const requiredFields = ['name', 'description', 'personality', 'scenario', 'first_mes', 'mes_example', 'creator_notes', 'system_prompt', 'post_history_instructions', 'alternate_greetings', 'tags', 'creator', 'character_version', 'extensions'];
+        const isAllRequiredFieldsPresent = requiredFields.every(field => {
+            if (!data.hasOwnProperty(field)) {
+                this.#validationError = `data.${field}`;
+                return false;
+            }
+            return true;
+        });
+
+        return isAllRequiredFieldsPresent && Array.isArray(data.alternate_greetings) && Array.isArray(data.tags) && typeof data.extensions === 'object';
+    }
+
+    #validateCharacterBook() {
+        const characterBook = this.card.data.character_book;
+
+        if (!characterBook) {
+            return true;
+        }
+
+        const requiredFields = ['extensions', 'entries'];
+        const isAllRequiredFieldsPresent = requiredFields.every(field => {
+            if (!characterBook.hasOwnProperty(field)) {
+                this.#validationError = `data.character_book.${field}`;
+                return false;
+            }
+            return true;
+        });
+
+        return isAllRequiredFieldsPresent && Array.isArray(characterBook.entries) && typeof characterBook.extensions === 'object';
+    }
+}
+
+module.exports = {TavernCardValidator}