Fragmented Hook Types: Unify inconsistent hook integration points

[thomhurst]

Problem

Pipeline hooks use inconsistent context types across different integration points:

• Module Hooks (IPipelineModuleHooks): Receive IPipelineHookContext + IModule
• Global Hooks (IPipelineGlobalHooks): Receive IPipelineHookContext + IPipelineSummary
• Attribute Events: Receive different context per event receiver class
• Context Extensions: Tool-specific extensions don't support hooks

This causes:

• Inconsistency: Same concept (before/after) has different signatures
• Confusion: Unclear which context object to use when
• Fragmentation: Hooks scattered across multiple interfaces
• Integration Difficulty: Hard to add hooks to custom tool integrations

Current Design

// Module hooks with one signature
public interface IPipelineModuleHooks
{
    Task OnBeforeModuleStartAsync(IPipelineHookContext context, IModule module);
    Task OnAfterModuleEndAsync(IPipelineHookContext context, IModule module);
}

// Global hooks with different signature
public interface IPipelineGlobalHooks
{
    Task OnStartAsync(IPipelineHookContext context);
    Task OnEndAsync(IPipelineHookContext context, PipelineSummary summary);
}

Proposed Solution

Unified hook interface with clear stages:

public interface IPipelineHooks
{
    Task OnPipelineStartingAsync(IPipelineContext context);
    Task OnModuleStartingAsync(IPipelineContext context, IModule module);
    Task OnModuleCompletedAsync(IPipelineContext context, IModule module, ModuleResult result);
    Task OnPipelineCompletedAsync(IPipelineContext context, PipelineSummary summary);
}

public class PipelineConfiguration
{
    public void AddHooks<THooks>() where THooks : IPipelineHooks;
}

Benefits

• Consistent hook interface across all stages
• Clear naming convention for lifecycle stages
• Single place to understand all hooks
• Easier to implement custom hooks
• Better composition

Priority: MEDIUM - Breaking change, improves consistency