Struct ThinkingDeltaRenderer 

pub struct ThinkingDeltaRenderer;

Renderer for streaming thinking deltas.

Supports the same append-only pattern as TextDeltaRenderer:

• First delta: prefix + “Thinking: “ + content (no newline)
• Subsequent deltas: Parser computes and emits only new suffix
• Completion: single newline via DeltaRenderer::render_completion

Append-Only Pattern

For true append-only streaming in Full mode, parsers should:

1. Call render_first_delta for the first thinking delta (shows prefix + content)
2. Track last rendered content and emit only new suffixes directly (bypass render_subsequent_delta)
3. Call render_completion when thinking completes (adds final newline)

This avoids cursor movement and works correctly under terminal wrapping.

CCS Spam Prevention (Bug Fix)

Like TextDeltaRenderer, this implementation suppresses per-delta output in non-TTY modes to prevent repeated “[ccs/codex] Thinking:” and “[ccs/glm] Thinking:” lines in logs. The fix is validated with ultra-extreme streaming tests (1000+ thinking deltas).

See comprehensive regression tests:

• tests/integration_tests/ccs_delta_spam_systematic_reproduction.rs (NEW: systematic reproduction test)
• tests/integration_tests/ccs_all_delta_types_spam_reproduction.rs (1000+ deltas, rapid succession, interleaved blocks)
• tests/integration_tests/ccs_extreme_streaming_regression.rs (500+ deltas per block)
• tests/integration_tests/ccs_streaming_spam_all_deltas.rs (all delta types)
• tests/integration_tests/codex_reasoning_spam_regression.rs (original reasoning fix)

Trait Implementations

impl DeltaRenderer for ThinkingDeltaRenderer

fn render_first_delta( accumulated: &str, prefix: &str, colors: Colors, terminal_mode: TerminalMode, ) -> String

Render the first delta of a content block.

fn render_subsequent_delta( _accumulated: &str, _prefix: &str, _colors: Colors, terminal_mode: TerminalMode, ) -> String

Render a subsequent delta (in-place update).

fn render_completion(terminal_mode: TerminalMode) -> String

Render the completion of streaming.