Schema (#120)

* Enhance schema config to more accurately valid config files before linting

* Update ConfigSchema.js

Author: tclindner

src/config/ConfigSchema.js

@@ -1,36 +1,224 @@
+const Ajv = require('ajv');
+const ajvErrors = require('ajv-errors');
+
+const ajv = new Ajv({allErrors: true, jsonPointers: true});
+
+ajvErrors(ajv);
+
 /**
- * Top level config properties
- * @type {Object}
+ * Formats an array of schema validation errors.
+ *
+ * @param {Array} errors An array of error messages to format.
+ * @returns {String} Formatted error message
  */
-const topLevelConfigProperties = {
-  extends: {type: ['string', 'array']},
-  rules: {type: 'object'},
-  root: {type: 'boolean'}
+const formatSchemaErrors = errors => {
+  return errors.map(error => `\t- ${error.message}\n`).join('');
+};
+
+const standardRuleSchema = {
+  type: 'string',
+  enum: ['off', 'warning', 'error'],
+  errorMessage: {
+    type: 'severity must be a string.',
+    enum: 'severity must be either "off", "warning", or "error".'
+  }
+};
+
+const arrayRuleSchema = {
+  type: 'array',
+  items: [
+    standardRuleSchema,
+    {
+      type: 'array',
+      minItems: 1,
+      uniqueItems: true,
+      errorMessage: {
+        type: 'the second item in an array rule config must be an array.',
+        minItems: 'the second item in an array rule config must have at least 1 item.',
+        uniqueItems: 'the second item in an array rule config must have unique items.'
+      }
+    }
+  ],
+  minItems: 2,
+  maxItems: 2,
+  additionalItems: false,
+  errorMessage: {
+    type: 'rule config must be an array, e.g. ["error", ["value1", "value2"]].',
+    minItems: 'array rules must have two items, severity and options array. e.g. ["error", ["value1", "value2"]].',
+    maxItems: 'array rules must have two items, severity and options array. e.g. ["error", ["value1", "value2"]].',
+    additionalItems:
+      'array rules are only allowed two items, severity and the list is values. e.g. ["error", ["value1", "value2"]].'
+  }
+};
+
+const objectRuleSchema = {
+  type: 'array',
+  items: [
+    standardRuleSchema,
+    {
+      type: 'object',
+      errorMessage: {
+        type: 'the second item in an object rule config must be an object.'
+      }
+    }
+  ],
+  minItems: 2,
+  maxItems: 2,
+  additionalItems: false,
+  errorMessage: {
+    type: 'rule config must be an array, e.g. ["error", {}].',
+    minItems: 'object rules must have two items, severity and options object. e.g. ["error", {}].',
+    maxItems: 'object rules must have two items, severity and options object. e.g. ["error", {}].',
+    additionalItems: 'object rules are only allowed two items, severity and options object. e.g. ["error", {}].'
+  }
+};
+
+const optionalObjExceptionsSchema = {
+  type: 'array',
+  items: [
+    {
+      type: 'string',
+      errorMessage: {
+        type: 'each exception must be a string.'
+      }
+    }
+  ],
+  uniqueItems: true,
+  minItems: 1,
+  errorMessage: {
+    type: 'expections must be an array.',
+    minItems: 'expections must have at least 1 item.',
+    uniqueItems: 'expections must have unique items.'
+  }
 };
 
-/**
- * Config schema defintion
- * @type {Object}
- */
 const configurationSchema = {
   type: 'object',
-  properties: topLevelConfigProperties,
-  additionalProperties: false
+  properties: {
+    extends: {
+      type: ['string', 'array'],
+      items: {
+        type: 'string'
+      },
+      minItems: 1,
+      uniqueItems: true,
+      errorMessage: {
+        type: 'extends must be either a string or an array of strings.',
+        minItems: 'extends must have at least one item if it is an array.',
+        uniqueItems: 'extends must have unique items if it is an array.'
+      }
+    },
+    rules: {
+      type: 'object',
+      errorMessage: {
+        type: 'rules must be an object.'
+      }
+    },
+    root: {
+      type: 'boolean',
+      errorMessage: {
+        type: 'root must be a boolean.'
+      }
+    }
+  },
+  additionalProperties: false,
+  errorMessage: {
+    type: 'npm-package-json-lint config should be an object.',
+    additionalProperties:
+      'npm-package-json-lint config has unexpected top-level property. Valid properties include: `extends`, `rules`, and `root`.'
+  }
+};
+
+/**
+ * Validates standard rules config.
+ *
+ * @param {Object} ruleConfig The ruleConfig object to validate.
+ * @returns {boolean} True if valid. Error if not.
+ */
+const isStandardRuleSchemaValid = ruleConfig => {
+  const validate = ajv.compile(standardRuleSchema);
+  const isValid = validate(ruleConfig);
+
+  if (!isValid) {
+    throw new Error(`${formatSchemaErrors(validate.errors)}`);
+  }
+
+  return true;
+};
+
+/**
+ * Validates array rules config.
+ *
+ * @param {Object} ruleConfig The ruleConfig object to validate.
+ * @returns {boolean} True if valid. Error if not.
+ */
+const isArrayRuleSchemaValid = ruleConfig => {
+  const validate = ajv.compile(arrayRuleSchema);
+  const isValid = validate(ruleConfig);
+
+  if (!isValid) {
+    throw new Error(`${formatSchemaErrors(validate.errors)}`);
+  }
+
+  return true;
+};
+
+/**
+ * Validates array rules config.
+ *
+ * @param {Object} ruleConfig The ruleConfig object to validate.
+ * @returns {boolean} True if valid. Error if not.
+ */
+const isObjectRuleSchemaValid = ruleConfig => {
+  const validate = ajv.compile(objectRuleSchema);
+  const isValid = validate(ruleConfig);
+
+  if (!isValid) {
+    throw new Error(`${formatSchemaErrors(validate.errors)}`);
+  }
+
+  return true;
 };
 
 /**
- * Public ConfigSchema class
- * @class
+ * Validates optional object exceptions config.
+ *
+ * @param {Object} ruleConfig The ruleConfig object to validate.
+ * @returns {boolean} True if valid. Error if not.
  */
-class ConfigSchema {
-  /**
-   * Gets configuration schema
-   *
-   * @returns {Object} schema object
-   */
-  static get() {
-    return configurationSchema;
-  }
-}
-
-module.exports = ConfigSchema;
+const isOptionalObjExceptSchemaValid = ruleConfig => {
+  const validate = ajv.compile(optionalObjExceptionsSchema);
+  const isValid = validate(ruleConfig);
+
+  if (!isValid) {
+    throw new Error(`${formatSchemaErrors(validate.errors)}`);
+  }
+
+  return true;
+};
+
+/**
+ * Validates the top level properties of the config object.
+ *
+ * @param {Object} config The config object to validate.
+ * @param {string} source The name of the configuration source to report in any errors.
+ * @returns {boolean} True if valid. Error if not.
+ */
+const isConfigObjectSchemaValid = (config, source) => {
+  const validate = ajv.compile(configurationSchema);
+  const isValid = validate(config);
+
+  if (!isValid) {
+    throw new Error(`npm-package-json-lint configuration in ${source} is invalid:\n${formatSchemaErrors(validate.errors)}`);
+  }
+
+  return true;
+};
+
+module.exports = {
+  isConfigObjectSchemaValid,
+  isStandardRuleSchemaValid,
+  isArrayRuleSchemaValid,
+  isObjectRuleSchemaValid,
+  isOptionalObjExceptSchemaValid
+};