Test Case Configuration
Define evaluation scenarios with variables, assertions, and test data.
Inline Tests
The simplest way to define tests is directly in your config:
tests:
- vars:
question: 'What is the capital of France?'
assert:
- type: contains
value: 'Paris'
- vars:
question: 'What is 2 + 2?'
assert:
- type: equals
value: '4'
Test Structure
Each test case can include:
tests:
- description: 'Optional test description'
vars:
# Variables to substitute in prompts
var1: value1
var2: value2
assert:
# Expected outputs and validations
- type: contains
value: 'expected text'
metadata:
# Filterable metadata
category: math
difficulty: easy
External Test Files
For larger test suites, store tests in separate files:
tests: file://tests.yaml
Or load multiple files:
tests:
- file://basic_tests.yaml
- file://advanced_tests.yaml
- file://edge_cases/*.yaml
CSV Format
CSV or Excel (XLSX) files are ideal for bulk test data:
tests: file://test_cases.csv
tests: file://test_cases.xlsx
Basic CSV
question,expectedAnswer
"What is 2+2?","4"
"What is the capital of France?","Paris"
"Who wrote Romeo and Juliet?","Shakespeare"
Variables are automatically mapped from column headers.
Excel (XLSX/XLS) Support
Excel files (.xlsx and .xls) are supported as an optional feature. To use Excel files:
-
Install the
xlsxpackage as a peer dependency:# Install latest version from npm (recommended)
npm install xlsx
# OR install specific version from SheetJS CDN
npm install https://cdn.sheetjs.com/xlsx-0.18.5/xlsx-0.18.5.tgzWhy two options?
- npm install xlsx: Gets version 0.18.5 from npm registry (recommended for most users)
- CDN URL: Installs the same version from SheetJS CDN for environments that prefer CDN sources
-
Use Excel files just like CSV files:
promptfooconfig.yamltests: file://test_cases.xlsx
Multi-sheet support: By default, only the first sheet is used. To specify a different sheet, use the # syntax:
file://test_cases.xlsx#Sheet2- Select sheet by namefile://test_cases.xlsx#2- Select sheet by 1-based index (2 = second sheet)
# Use a specific sheet by name
tests: file://test_cases.xlsx#DataSheet
# Or by index (1-based)
tests: file://test_cases.xlsx#2
XLSX Example
Your Excel file should have column headers in the first row, with each subsequent row representing a test case:
| question | expectedAnswer |
|---|---|
| What is 2+2? | 4 |
| What is the capital of France? | Paris |
| Name a primary color | blue |
Tips for Excel files:
- First row must contain column headers
- Column names become variable names in your prompts
- Empty cells are treated as empty strings
- Use
__expectedcolumns for assertions (same as CSV)
CSV with Assertions
Use special __expected columns for assertions:
input,__expected
"Hello world","contains: Hello"
"Calculate 5 * 6","equals: 30"
"What's the weather?","llm-rubric: Provides weather information"
Multiple assertions:
question,__expected1,__expected2,__expected3
"What is 2+2?","equals: 4","contains: four","javascript: output.length < 10"
contains-any and contains-all expect comma-delimited values inside the __expected column.
translated_text,__expected
"<span>Hola</span> <b>mundo</b>","contains-any: <b>,</span>"
If you write "contains-any: <b> </span>", promptfoo treats <b> </span> as a single search term rather than two separate tags.
Special CSV Columns
| Column | Purpose | Example |
|---|---|---|
__expected | Single assertion | contains: Paris |
__expected1, __expected2, ... | Multiple assertions | equals: 42 |
__description | Test description | Basic math test |
__prefix | Prepend to prompt | You must answer: |
__suffix | Append to prompt | (be concise) |
__metric | Metric name for assertions | accuracy |
__threshold | Pass threshold (applies to all asserts) | 0.8 |
__metadata:* | Filterable metadata | See below |
__config:__expected:<key> or __config:__expectedN:<key> | Set configuration for all or specific assertions | __config:__expected:threshold, __config:__expected2:threshold |
Using __metadata without a key is not supported. Specify the metadata field like __metadata:category.
If a CSV file includes a __metadata column without a key, Promptfoo logs a warning and ignores the column.
Metadata in CSV
Add filterable metadata:
question,__expected,__metadata:category,__metadata:difficulty
"What is 2+2?","equals: 4","math","easy"
"Explain quantum physics","llm-rubric: Accurate explanation","science","hard"
Array metadata with []:
topic,__metadata:tags[]
"Machine learning","ai,technology,data science"
"Climate change","environment,science,global\,warming"
Filter tests:
promptfoo eval --filter-metadata category=math
promptfoo eval --filter-metadata difficulty=easy
promptfoo eval --filter-metadata tags=ai
JSON in CSV
Include structured data:
query,context,__expected
"What's the temperature?","{""location"":""NYC"",""units"":""celsius""}","contains: celsius"
Access in prompts:
prompts:
- 'Query: {{query}}, Location: {{(context | load).location}}'
Dynamic Test Generation
Generate tests programmatically:
JavaScript/TypeScript
tests: file://generate_tests.js
module.exports = async function () {
// Fetch data, compute test cases, etc.
const testCases = [];
for (let i = 1; i <= 10; i++) {
testCases.push({
description: `Test case ${i}`,
vars: {
number: i,
squared: i * i,
},
assert: [
{
type: 'contains',
value: String(i * i),
},
],
});
}
return testCases;
};
Python
tests: file://generate_tests.py:create_tests
import json
def create_tests():
test_cases = []
# Load test data from database, API, etc.
test_data = load_test_data()
for item in test_data:
test_cases.append({
"vars": {
"input": item["input"],
"context": item["context"]
},
"assert": [{
"type": "contains",
"value": item["expected"]
}]
})
return test_cases
With Configuration
Pass configuration to generators:
tests:
- path: file://generate_tests.py:create_tests
config:
dataset: 'validation'
category: 'math'
sample_size: 100
def create_tests(config):
dataset = config.get('dataset', 'train')
category = config.get('category', 'all')
size = config.get('sample_size', 50)
# Use configuration to generate tests
return generate_test_cases(dataset, category, size)
JSON/JSONL Format
JSON Array
[
{
"vars": {
"topic": "artificial intelligence"
},
"assert": [
{
"type": "contains",
"value": "AI"
}
]
},
{
"vars": {
"topic": "climate change"
},
"assert": [
{
"type": "llm-rubric",
"value": "Discusses environmental impact"
}
]
}
]
JSONL (One test per line)
{"vars": {"x": 5, "y": 3}, "assert": [{"type": "equals", "value": "8"}]}
{"vars": {"x": 10, "y": 7}, "assert": [{"type": "equals", "value": "17"}]}
Loading Media Files
Include images, PDFs, and other files as variables:
tests:
- vars:
image: file://images/chart.png
document: file://docs/report.pdf
data: file://data/config.yaml
Supported File Types
| Type | Handling | Usage |
|---|---|---|
| Images (png, jpg, etc.) | Converted to base64 | Vision models |
| Videos (mp4, etc.) | Converted to base64 | Multimodal models |
| PDFs | Text extraction | Document analysis |
| Text files | Loaded as string | Any use case |
| YAML/JSON | Parsed to object | Structured data |
Example: Vision Model Test
tests:
- vars:
image: file://test_image.jpg
question: 'What objects are in this image?'
assert:
- type: contains
value: 'dog'
In your prompt:
[
{
"role": "user",
"content": [
{ "type": "text", "text": "{{question}}" },
{
"type": "image_url",
"image_url": {
"url": "data:image/jpeg;base64,{{image}}"
}
}
]
}
]
Best Practices
1. Organize Test Data
project/
├── promptfooconfig.yaml
├── prompts/
│ └── main_prompt.txt
└── tests/
├── basic_functionality.csv
├── edge_cases.yaml
└── regression_tests.json
2. Use Descriptive Names
tests:
- description: 'Test French translation with formal tone'
vars:
text: 'Hello'
language: 'French'
tone: 'formal'
3. Group Related Tests
# Use metadata for organization
tests:
- vars:
query: 'Reset password'
metadata:
feature: authentication
priority: high
4. Combine Approaches
tests:
# Quick smoke tests inline
- vars:
test: 'quick check'
# Comprehensive test suite from file
- file://tests/full_suite.csv
# Dynamic edge case generation
- file://tests/generate_edge_cases.js
Common Patterns
A/B Testing Variables
message_style,greeting,__expected
"formal","Good morning","contains: Good morning"
"casual","Hey there","contains: Hey"
"friendly","Hello!","contains: Hello"
Error Handling Tests
tests:
- description: 'Handle empty input'
vars:
input: ''
assert:
- type: contains
value: 'provide more information'
Performance Tests
tests:
- vars:
prompt: 'Simple question'
assert:
- type: latency
threshold: 1000 # milliseconds
External Data Sources
Google Sheets
See Google Sheets integration for details on loading test data directly from spreadsheets.
SharePoint
See SharePoint integration for details on loading test data from Microsoft SharePoint document libraries.
HuggingFace Datasets
See HuggingFace Datasets for instructions on importing test cases from existing datasets.