1 files changed, 71 insertions, 0 deletions
diff --git a/src/lib/data-validator.js b/src/lib/data-validator.js
new file mode 100644
index 0000000..276ea9b
--- /dev/null
+++ b/src/lib/data-validator.js
@@ -0,0 +1,71 @@
+const {isInteger, isObject} = require('lodash')
+const {getLogger} = require('./logger')
+
+const typeNames = {
+    'i': 'integer',
+    'n': 'number',
+    's': 'string',
+    'o': 'object',
+    'a': 'array',
+}
+
+const logger = getLogger('data-validator')
+
+/**
+ * @param {string} expectedType
+ * @param value
+ */
+function checkType(expectedType, value) {
+    switch (expectedType) {
+        case 'i':
+            return isInteger(value)
+        case 'n':
+            return typeof value === 'number'
+        case 's':
+            return typeof value === 'string'
+        case 'o':
+            return typeof value === 'object'
+        case 'a':
+            return Array.isArray(value)
+        default:
+            logger.error(`checkType: unknown type ${expectedType}`)
+            return false
+    }
+}
+
+/**
+ * @param {object} data
+ * @param {array} schema
+ */
+function validateMessageData(data, schema) {
+    if (!isObject(data))
+        throw new Error(`data is not an object`)
+
+    for (const field of schema) {
+        let [name, types, required] = field
+        if (!(name in data)) {
+            if (required)
+                throw new Error(`missing required field ${name}`)
+
+            continue
+        }
+
+        types = types.split('')
+
+        if (!types
+            .map(type => checkType(type, data[name]))
+            .some(result => result === true)) {
+
+            let error = `'${name}' must be `
+            if (types.length === 1) {
+                error += typeNames[types[0]]
+            } else {
+                error += 'any of: ' + types.map(t => typeNames[t]).join(', ')
+            }
+
+            throw new Error(error)
+        }
+    }
+}
+
+module.exports = {validateMessageData}
+\ No newline at end of file