Data Validation

Data validation is the foundation of gRPC testing. Learn how to validate response data, test different data types, and handle complex nested structures.

Basic Data Validation

Simple Response Validation

Test basic response data:

php

--- ENDPOINT ---
user.UserService/GetUser

--- REQUEST ---
{ "user_id": "123" }

--- RESPONSE ---
{
  "user": {
    "id": "123",
    "name": "John Doe",
    "email": "john@example.com"
  }
}

Using Assertions for Flexible Validation

For more dynamic validation, use assertions:

php

--- ENDPOINT ---
user.UserService/GetUser

--- REQUEST ---
{ "user_id": "123" }

--- ASSERTS ---
.user.id == "123"
.user.name == "John Doe"
.user.email | contains("@")

Type Validation

Ensure response fields have correct types:

php

--- ENDPOINT ---
product.ProductService/GetProduct

--- REQUEST ---
{ "product_id": "prod_001" }

--- ASSERTS ---
# String validation
.product.id | type == "string"
.product.name | type == "string"

# Number validation
.product.price | type == "number"
.product.price > 0
.product.stock_count | type == "number"
.product.stock_count >= 0

# Boolean validation
.product.in_stock | type == "boolean"
.product.featured | type == "boolean"

Array Validation

Testing responses with arrays:

php

--- ENDPOINT ---
product.ProductService/ListProducts

--- REQUEST ---
{ "category": "electronics" }

--- ASSERTS ---
# Array length
.products | length > 0
.products | length <= 100

# Array element validation
.products[0].id | length > 0
.products[0].name | type == "string"
.products[0].price > 0

# All products have required fields
.products[] | has("id")
.products[] | has("name")
.products[] | has("price")

# Price validation for all products
.products[].price > 0

Nested Object Validation

Testing complex nested structures:

php

--- ENDPOINT ---
order.OrderService/GetOrderDetails

--- REQUEST ---
{ "order_id": "order_001" }

--- ASSERTS ---
# Top-level validation
.order.id == "order_001"
.order.status | type == "string"

# Nested customer validation
.order.customer.name == "John Doe"
.order.customer.email | contains("@")
.order.customer.id | length > 0

# Array of items validation
.order.items | length > 0
.order.items[0].quantity > 0
.order.items[0].price > 0
.order.items[0].product_id | length > 0

# Nested shipping validation
.order.shipping.city == "Moscow"
.order.shipping.country == "Russia"
.order.shipping.zip_code | length > 0

String Validation

Advanced string validation techniques:

php

--- ASSERTS ---
# Exact match
.name == "John Doe"

# Contains substring
.description | contains("important")

# Starts with
.email | startswith("john")

# Ends with
.filename | endswith(".pdf")

# Length validation
.password | length >= 8
.username | length <= 20

# Pattern matching (regex)
.email | test("^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$")
.phone | test("^\\+?[1-9]\\d{1,14}$")

Number Validation

Comprehensive number validation:

php

--- ASSERTS ---
# Exact value
.count == 42

# Range validation
.age >= 18
.age <= 120
.price > 0
.price <= 9999.99

# Type checking
.score | type == "number"
.rating | type == "number"

# Mathematical operations
.total == (.subtotal + .tax)
.discount_percent >= 0
.discount_percent <= 100

Boolean Validation

Testing boolean fields:

php

--- ASSERTS ---
# Exact boolean values
.is_active == true
.is_deleted == false

# Type checking
.verified | type == "boolean"
.premium | type == "boolean"

# Logical combinations
.is_active and .verified
not .is_deleted

Null and Optional Fields

Handling null values and optional fields:

php

--- ASSERTS ---
# Check for null
.middle_name == null

# Check for non-null
.first_name != null
.last_name != null

# Optional field validation
if has("optional_field") then .optional_field | length > 0 else true

# Conditional validation
if .type == "premium" then .premium_features | length > 0 else true

Best Practices

✅ Do This:

Validate Critical Fields

php

--- ASSERTS ---
.id | length > 0
.name | type == "string"
.created_at | length > 0

Use Type Validation

php

--- ASSERTS ---
.price | type == "number"
.price > 0

Validate Arrays Comprehensively

php

--- ASSERTS ---
.items | length > 0
.items[] | has("id")
.items[].price > 0

Test Nested Objects

php

--- ASSERTS ---
.user.name | length > 0
.user.email | contains("@")

❌ Avoid This:

Hard-coded Values

php

# Bad
.created_at == "2024-01-15T10:30:00Z"

# Good
.created_at | length > 0
.created_at | contains("T")

Incomplete Validation

php

# Bad - only checking one field
.user.name == "John"

# Good - comprehensive validation
.user.name == "John"
.user.id | length > 0
.user.email | contains("@")

Ignoring Type Safety

php

# Bad - no type checking
.count > 0

# Good - type validation first
.count | type == "number"
.count > 0

Common Patterns

User Data Validation

php

--- ASSERTS ---
.user.id | length > 0
.user.name | type == "string"
.user.name | length > 0
.user.email | contains("@")
.user.email | contains(".")
.user.created_at | length > 0

Product Data Validation

php

--- ASSERTS ---
.product.id | length > 0
.product.name | type == "string"
.product.name | length > 0
.product.price | type == "number"
.product.price > 0
.product.category | type == "string"
.product.in_stock | type == "boolean"

Order Data Validation

php

--- ASSERTS ---
.order.id | length > 0
.order.status | type == "string"
.order.total | type == "number"
.order.total > 0
.order.items | length > 0
.order.items[] | has("id")
.order.items[].quantity > 0
.order.items[].price > 0

Next Steps

Error Testing - Learn to test error conditions
Assertion Patterns - Master advanced validation techniques
Real Examples - See data validation in action

Data Validation ​

Basic Data Validation ​

Simple Response Validation ​

Using Assertions for Flexible Validation ​

Type Validation ​

Array Validation ​

Nested Object Validation ​

String Validation ​

Number Validation ​

Boolean Validation ​

Null and Optional Fields ​

Best Practices ​

✅ Do This: ​

❌ Avoid This: ​

Common Patterns ​

User Data Validation ​

Product Data Validation ​

Order Data Validation ​

Next Steps ​