Function persistInterruptedStep

coderd/x/chatd/chatloop/chatloop.go:1705–1796

persistInterruptedStep saves durable content from a partial stream. Provider-executed calls without results are removed because their result metadata cannot be synthesized safely, except when removal would mutate signed Anthropic replay state.

(
	ctx context.Context,
	opts RunOptions,
	result *stepResult,
)

// metadata cannot be synthesized safely, except when removal would mutate
// signed Anthropic replay state.
func persistInterruptedStep(
	ctx context.Context,
	opts RunOptions,
	result *stepResult,
) {
	if result == nil || (len(result.content) == 0 && len(result.toolCalls) == 0) {
		return
	}

	provider := ""
	modelName := ""
	if opts.Model != nil {
		provider = opts.Model.Provider()
		modelName = opts.Model.Model()
	}
	var sanitizeStats chatsanitize.AnthropicProviderToolSanitizationStats
	result.content, sanitizeStats = chatsanitize.SanitizeAnthropicProviderToolContent(provider, result.content)
	chatsanitize.LogAnthropicProviderToolSanitization(
		ctx, opts.Logger, "interrupted_persist", provider, modelName, sanitizeStats,
	)

	// Track which tool calls already have results in the content.
	answeredToolCalls := make(map[string]struct{})
	for _, c := range result.content {
		tr, ok := fantasy.AsContentType[fantasy.ToolResultContent](c)
		if ok && tr.ToolCallID != "" {
			answeredToolCalls[tr.ToolCallID] = struct{}{}
		}
	}

	// Copy existing timestamps and add result timestamps for
	// interrupted tool calls so the frontend can show partial
	// duration.
	toolCallCreatedAt := maps.Clone(result.toolCallCreatedAt)
	if toolCallCreatedAt == nil {
		toolCallCreatedAt = make(map[string]time.Time)
	}
	toolResultCreatedAt := maps.Clone(result.toolResultCreatedAt)
	if toolResultCreatedAt == nil {
		toolResultCreatedAt = make(map[string]time.Time)
	}

	// Build combined content: all accumulated content + synthetic
	// interrupted results for any unanswered tool calls.
	content := make([]fantasy.Content, 0, len(result.content))
	content = append(content, result.content...)

	interruptedAt := dbtime.Now()
	for _, tc := range result.toolCalls {
		if tc.ToolCallID == "" {
			continue
		}
		if _, exists := answeredToolCalls[tc.ToolCallID]; exists {
			continue
		}
		if chatsanitize.IsAnthropicProviderExecutedToolCall(provider, tc) {
			continue
		}