fix(logs): parse compute string for aggregate metrics

[platinummonkey]

Summary

Fixes #35

The pup logs aggregate --compute flag now properly parses metric-based aggregation functions like avg(@duration), sum(@bytes), etc. Previously, the entire compute string was passed as-is to the aggregation function field, causing 400 errors from the Datadog API.

Changes

Core Fix (cmd/logs_simple.go:641-690)

• Added parseComputeString() helper to extract aggregation function and metric from compute strings
• Supports formats: "count", "avg(@duration)", "percentile(@duration, 99)"
• Validates aggregation functions against API-supported list
• Handles case-insensitive input and whitespace

Updated runLogsAggregate (cmd/logs_simple.go:954-1035)

• Parse compute string before building API request
• Properly set aggregation function and metric fields
• Enhanced error messages with detailed request info and troubleshooting tips

Test Coverage (cmd/logs_simple_test.go:84-228)

• Added 16 test cases covering all compute string formats
• Tests for valid functions: count, avg, sum, min, max, cardinality, median, percentile
• Tests for error cases: invalid functions, malformed strings, empty input
• Tests for edge cases: whitespace, case sensitivity, complex metric names

Examples

Now working:

# Average duration by service
pup logs aggregate --query="*" --from="1h" --compute="avg(@duration)" --group-by="service"

# Unique user count
pup logs aggregate --query="service:web" --from="4h" --compute="cardinality(@user.id)"

# 99th percentile latency
pup logs aggregate --query="*" --from="2h" --compute="percentile(@latency, 99)"

# Sum of bytes by host
pup logs aggregate --query="*" --from="1d" --compute="sum(@bytes)" --group-by="host"

Testing

All tests pass with race detection:

go test -race ./cmd/...

Specific test for this fix:

go test -v -run TestParseComputeString ./cmd/

Error Message Improvements

Enhanced error messages now include:

• Parsed compute details (aggregation + metric)
• Full request parameters
• Formatted timestamps
• Troubleshooting tips
• Supported function list

---

🤖 Generated with Claude Code

[github-actions]

📊 Test Coverage Report

Overall Coverage: 80.4%

Threshold: 80% ✅

Coverage by Package

## Coverage by Package

- github.com/DataDog/pup/pkg/auth/callback/server.go:40: 81.2%
- github.com/DataDog/pup/pkg/auth/dcr/client.go:28: 100.0%
- github.com/DataDog/pup/pkg/auth/dcr/types.go:24: 100.0%
- github.com/DataDog/pup/pkg/auth/oauth/client.go:22: 100.0%
- github.com/DataDog/pup/pkg/auth/oauth/pkce.go:24: 85.7%
- github.com/DataDog/pup/pkg/auth/storage/factory.go:53: 94.7%
- github.com/DataDog/pup/pkg/auth/storage/keychain.go:44: 42.9%
- github.com/DataDog/pup/pkg/auth/storage/storage.go:58: 71.4%
- github.com/DataDog/pup/pkg/auth/types/types.go:23: 100.0%
- github.com/DataDog/pup/pkg/client/client.go:32: 94.4%
- github.com/DataDog/pup/pkg/config/config.go:22: 100.0%
- github.com/DataDog/pup/pkg/formatter/formatter.go:31: 100.0%
- github.com/DataDog/pup/pkg/useragent/useragent.go:32: 100.0%
- github.com/DataDog/pup/pkg/util/time.go:20: 95.8%

## Summary

total:								(statements)		80.4%

---

📈 Coverage Status: ✅ PASSED - Coverage meets minimum threshold

_{Updated for commit b96c9bb}