1 files changed, 77 insertions, 0 deletions
diff --git a/app_expo/utils/validate.ts b/app_expo/utils/validate.ts
new file mode 100644
index 0000000..838c0c1
--- /dev/null
+++ b/app_expo/utils/validate.ts
@@ -0,0 +1,77 @@
+const ValidateJS = require('validate.js')
+
+// HACK(steve): wierd typescript situation because of strange typings
+const Validate: any = ValidateJS.default ? ValidateJS.default : ValidateJS
+
+/**
+ * Validates that 1 attribute doesn't appear in another's attributes content.
+ */
+Validate.validators.excludes = function custom(value, options, key, attributes) {
+  const list = attributes[options.attribute] || []
+  if (value && list.includes(value)) {
+    return options.message || `${value} is in the list`
+  }
+}
+
+/**
+ * Validates that another attribute isn't true.
+ */
+Validate.validators.tripped = function custom(value, options, key, attributes) {
+  if (value && attributes[options.attribute] === true) {
+    return options.message || `${options.attribute} is true`
+  }
+}
+
+/**
+ * Defines the rules for validating.
+ *
+ * Example:
+ * ```ts
+ * const RULES = {
+ *   favoriteBand: {
+ *     inclusion: { ['Weezer', 'Other'], message: 'Pick wisely.' }
+ *   },
+ *   name: {
+ *     presence: { message: 'A developer has no name?' }
+ *   }
+ * }
+ * validate(RULES, {})
+ * ```
+ *
+ * See https://validatejs.org/#validators for more examples.
+ *
+ */
+export interface ValidationRules {
+  [key: string]: Record<string, unknown>
+}
+
+/**
+ * An object containing any errors found.
+ *
+ * Example:
+ * ```js
+ * {
+ *   email: ['Invalid email address.'],
+ *   password: [
+ *     'Password must be 6 characters.',
+ *     'Password must have at least 1 digit.'
+ *   ]
+ * }
+ * ```
+ */
+export interface ValidationErrors {
+  [key: string]: string[]
+}
+
+/**
+ * Runs the given rules against the data object.
+ *
+ * @param rules The rules to apply.
+ * @param data The object to validate.
+ */
+export function validate(rules: ValidationRules, data: Record<string, unknown>): ValidationErrors {
+  if (typeof data !== 'object') {
+    return {} as ValidationErrors
+  }
+  return Validate(data, rules, { fullMessages: false }) || {}
+}