error-handling.md

error-handling.md

Section Inventory

Section	Core	Python	Py#	TypeScript	TS#	Ruby	Rb#	Go	Go#
Overview	—	✓	1	✓	1	TODO	1	✓	1
Application Errors/Failures	—	✓	2	✓	2	TODO	2	✓	2
Non-Retryable Errors	—	✓	3	—	—	TODO	3	✓	3
Activity Errors	—	—	—	✓	3	—	—	—	—
Handling Activity Errors in Workflows	—	✓	4	✓	4	TODO	4	✓	4
Retry Configuration	—	✓	5	✓	5	TODO	5	✓	5
Timeout Configuration	—	✓	6	✓	6	TODO	6	✓	6
Workflow Failure	—	✓	7	✓	7	TODO	7	✓	7
Cancellation Handling in Activities	—	—	—	—	—	—	—	—	—
Idempotency Patterns	—	—	—	—	—	—	—	—	—
Best Practices	—	✓	8	✓	9	TODO	8	✓	8

Style Compliance

Language	Status	Notes
Python	✓ reference	—
TypeScript	✓ aligned	Uses log, has retry defaults note
Ruby	—	Not started
Go	✓ aligned	Go-style error handling (errors.As, error returns, no exceptions)

Status

Ruby notes:

• Temporalio::Error::ApplicationError with non_retryable: parameter
• Any non-ApplicationError exception in a workflow causes workflow task failure (retried), NOT workflow failure
• Activity exceptions auto-converted to ApplicationError
• Temporalio::RetryPolicy.new(max_interval:, initial_interval:, backoff_coefficient:, max_attempts:, non_retryable_error_types:)
• Timeouts: start_to_close_timeout, schedule_to_close_timeout, schedule_to_start_timeout (same as other SDKs)
• workflow_failure_exception_types on Worker or workflow_failure_exception_type on Workflow class
• next_retry_delay: parameter on ApplicationError to override retry interval

Go-specific notes:

• Go uses error returns (not exceptions) — if err != nil pattern
• Application Errors: temporal.NewApplicationError("msg", "type", details...) and temporal.NewNonRetryableApplicationError("msg", "type", cause, details...)
• Non-Retryable: Go has both temporal.NewNonRetryableApplicationError() and NonRetryableErrorTypes in RetryPolicy
• Handling Activity Errors: errors.As(err, &applicationErr) pattern — check *temporal.ApplicationError, *temporal.TimeoutError, *temporal.CanceledError, *temporal.PanicError
• Retry Config: temporal.RetryPolicy struct with InitialInterval, BackoffCoefficient, MaximumInterval, MaximumAttempts, NonRetryableErrorTypes
• Timeout Config: workflow.ActivityOptions with StartToCloseTimeout, ScheduleToCloseTimeout, etc.
• Workflow Failure: returning any error from a workflow function fails the workflow

Intentionally missing (—):

• Core column: error handling is implementation-specific
• Activity Errors: TS-specific section (Go covers in Handling Activity Errors)

Order alignment: ✓ Aligned — Ruby and Go# monotonically increase

Style alignment: ✅ Complete (Python, TypeScript, Go). Ruby: ~8 sections planned.