feat(diagnostics): add conditional trace writes

Author: robertvokac

CLAUDE.md

@@ -9,7 +9,7 @@
 ## Non-negotiable rules
 
 1. **Zero errors, zero warnings** before any commit. `cmake --build build --parallel 4` must be clean.
-2. **No test-count regression.** `scripts/run_component_tests.sh build` must show no failures. The verified baseline is 12,672 tests across 36 component executables and one integration executable; this floor should be raised as new tests are added and lowered only with an explicit, documented reason.
+2. **No test-count regression.** `scripts/run_component_tests.sh build` must show no failures. The verified baseline is 12,675 tests across 36 component executables and one integration executable; this floor should be raised as new tests are added and lowered only with an explicit, documented reason.
 3. **Push only to `feature/work`.** Never push to `develop` or `master`, and never create tags, without explicit per-action user approval.
 4. **SPDX header on every project source/header** — `// SPDX-License-Identifier: MIT` + copyright + .NET attribution. Vendored sources retain their upstream headers; Markdown uses an HTML SPDX comment where one is present.
 5. **Property naming:** always `getXxxProperty()` / `setXxxProperty()`. Exception: indexers

NEXT.md

@@ -4,9 +4,9 @@
 # NEXT.md
 
 *Last verified: 2026-07-25. Branch: `feature/work`. The P0 component-boundary
-repair, three P1 parity repairs, P1 portability revalidation, and nineteen bounded
+repair, three P1 parity repairs, P1 portability revalidation, and twenty bounded
 P2 API slices are complete: 41 physical modules, 90 production dependency
-edges, and 12,672 tests across 37 executables.*
+edges, and 12,675 tests across 37 executables.*
 
 This is the cold-start handoff for the next working session. Keep it focused
 on verified facts, remaining bounded work, and commands needed to resume.
@@ -28,7 +28,7 @@ Historical session detail belongs in git history and `plan.sqlite3`.
 - The ten-job selective consumer matrix, including a direct
   `Collections.Blocking` consumer, is green. Text.Json retains its target
   absence and negative include-leakage assertions.
-- The full native baseline is a warning-free build with 12,672 passing tests
+- The full native baseline is a warning-free build with 12,675 passing tests
   across 36 component executables and one integration executable.
 - `TaskT<TResult>::ContinueWith` now supports both action and result-producing
   callbacks. It runs inline on completion; `NotOn*` and `OnlyOn*` filter the
@@ -77,6 +77,9 @@ Historical session detail belongs in git history and `plan.sqlite3`.
 - `UTF7Encoding` implements RFC 2152 modified-Base64 conversion for BMP and
   astral Unicode, including optional direct characters and U+FFFD recovery for
   malformed shifts. UTF-7 remains obsolete and unsuitable for new protocols.
+- `Trace::WriteIf` and `Trace::WriteLineIf` now conditionally preserve the
+  existing stderr write/newline behavior; category and listener surfaces stay
+  intentionally deferred.
 - MinGW-w64 GCC 14-win32/CMake 3.31.6 and Emscripten 5.0.7/CMake 3.31.6 both
   compile the post-modular `All` graph and selective `Text.Json` libraries.
   This is compile-only evidence: cross tests were deliberately disabled.
@@ -85,7 +88,7 @@ Historical session detail belongs in git history and `plan.sqlite3`.
   ASan/LSan ownership scenarios, including 100 continuation teardowns, pass.
 
 The local `plan.sqlite3` snapshot contains 16,201 classified `task` rows and
-1,761 completed tickets. Ticket #1737 records the completed P0 split, tickets
+1,762 completed tickets. Ticket #1737 records the completed P0 split, tickets
 #1738/#1739 the MemoryStream and generic-continuation repairs, ticket #1740 the
 XML whitespace repair, #1741 the completed cross-build revalidation and
 `WebProxy` portability fix, #1742 focused sanitizer evidence, and #1743 the
@@ -99,8 +102,8 @@ for its equality-based item mutations, #1754 for its equality-based range
 queries, #1755 for its comparer-aware binary search, #1756 for its default
 range sort, #1757 for `BigInteger` bitwise operators, #1758 for signed
 `BigInteger` shifts, #1759 for byte-vector conversion, and #1760 for the
-`ImmutableList<T>` Builder core, and #1761 for RFC 2152 UTF-7; it is
-git-ignored and is not part of a fresh clone.
+`ImmutableList<T>` Builder core, #1761 for RFC 2152 UTF-7, and #1762 for
+conditional Trace writes; it is git-ignored and is not part of a fresh clone.
 
 ## P0 completion: restore Collections isolation
 

README.md

@@ -7,7 +7,7 @@ collector, or the complete .NET platform.
 
 The repository currently builds as 41 independently selectable CMake
 components. The verified Linux baseline on 2026-07-25 is a warning-free build
-with **12,672 passing tests across 37 test executables**.
+with **12,675 passing tests across 37 test executables**.
 
 ## What is included
 
@@ -181,7 +181,7 @@ Other platform evidence is narrower:
 
 | Platform/toolchain | Verified scope |
 |---|---|
-| Linux/GCC | Current full component build and all 12,672 tests. |
+| Linux/GCC | Current full component build and all 12,675 tests. |
 | Windows/MinGW | MinGW-w64 GCC 14-win32/CMake 3.31.6 compiled the post-component `All` and selective `Text.Json` library graphs under ticket #1741. GoogleTest was not cross-built and repository CI remains Ubuntu-only. |
 | Emscripten | Emscripten 5.0.7/CMake 3.31.6 compiled the post-component `All` and selective `Text.Json` library graphs under ticket #1741. Tests were not cross-built or run, and some runtime APIs deliberately throw `PlatformNotSupportedException`. |
 | macOS/Apple Clang | Real downstream Xcode 15.4 builds drove portability fixes on 2026-07-20; this repository has no macOS job or recorded full standalone test baseline. |

docs/CMakeComponents.md

@@ -131,7 +131,7 @@ are named `SharpRuntimeTests_<Component>`; genuinely cross-module scenarios
 are in `SharpRuntimeIntegrationTests`. CTest also discovers every individual
 GoogleTest case.
 
-The verified 2026-07-25 `All` baseline contains 12,672 tests across 36
+The verified 2026-07-25 `All` baseline contains 12,675 tests across 36
 component executables and one integration executable.
 
 ## Boundary validation and CI

modules/diagnostics/include/System/Diagnostics/Trace.hpp

@@ -14,8 +14,8 @@ namespace System::Diagnostics {
      * Partial C++ counterpart of .NET System.Diagnostics.Trace.
      *
      * @note Status: Partial — writes to std::cerr; no TraceListeners/TraceListenerCollection,
-     * no CorrelationManager, no Refreshing event, no WriteIf/WriteLineIf family, no
-     * category-suffixed Write/WriteLine overloads, and no object-typed Write/WriteLine
+     * no CorrelationManager, no Refreshing event, no category-suffixed Write/WriteLine
+     * overloads, and no object-typed Write/WriteLine
      * overloads. Real .NET's Trace and Debug share the same underlying static IndentLevel
      * state (both delegate to an internal TraceInternal class); this port keeps them as
      * separate, independently-tracked indent levels since Debug's provider-hook design isn't
@@ -79,6 +79,20 @@ namespace System::Diagnostics {
         /** @brief Writes a blank line to stderr. */
         static void WriteLine()                         { std::cerr << '\n'; }
 
+        /** @brief Writes @p message to stderr only when @p condition is true. */
+        static void WriteIf(bool condition, const std::string& message) {
+            if (condition) {
+                Write(message);
+            }
+        }
+
+        /** @brief Writes @p message and a newline to stderr only when @p condition is true. */
+        static void WriteLineIf(bool condition, const std::string& message) {
+            if (condition) {
+                WriteLine(message);
+            }
+        }
+
         /** @brief Writes an informational @p message prefixed with [Info]. */
         static void TraceInformation(const std::string& message) {
             std::cerr << "[Info]  " << message << '\n';

modules/diagnostics/tests/System/Diagnostics/TraceConditionalWriteTests.cpp

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) Robert Vokac and contributors
+// Portions based on .NET runtime API (MIT License, Copyright .NET Foundation and Contributors)
+#include <gtest/gtest.h>
+
+#include <iostream>
+#include <sstream>
+
+#include "System/Diagnostics/Trace.hpp"
+
+using System::Diagnostics::Trace;
+
+namespace {
+class CerrCapture final {
+    std::streambuf* previous_;
+    std::ostringstream captured_;
+
+public:
+    CerrCapture() : previous_(std::cerr.rdbuf(captured_.rdbuf())) {}
+    ~CerrCapture() { std::cerr.rdbuf(previous_); }
+
+    [[nodiscard]] std::string getCaptured() const { return captured_.str(); }
+};
+} // namespace
+
+TEST(TraceConditionalWriteTest, FalseConditionsDoNotWrite) {
+    CerrCapture capture;
+
+    Trace::WriteIf(false, "hidden");
+    Trace::WriteLineIf(false, "also hidden");
+    Trace::Flush();
+
+    EXPECT_TRUE(capture.getCaptured().empty());
+}
+
+TEST(TraceConditionalWriteTest, WriteIfWritesWithoutTrailingNewline) {
+    CerrCapture capture;
+
+    Trace::WriteIf(true, "visible");
+    Trace::Flush();
+
+    EXPECT_EQ(capture.getCaptured(), "visible");
+}
+
+TEST(TraceConditionalWriteTest, WriteLineIfWritesWithTrailingNewline) {
+    CerrCapture capture;
+
+    Trace::WriteLineIf(true, "visible");
+    Trace::Flush();
+
+    EXPECT_EQ(capture.getCaptured(), "visible\n");
+}

plan.md

@@ -1,7 +1,7 @@
 # Sharp Runtime plan
 
 *Last verified: 2026-07-25 — 41 physical components, 90 direct production
-dependency edges, a clean native build, 12,672 passing tests across 37
+dependency edges, a clean native build, 12,675 passing tests across 37
 executables, and a green ten-job selective matrix.*
 
 Sharp Runtime is in a consumer-driven expansion phase. The original type
@@ -32,7 +32,7 @@ was never created. Neither file should be linked as current documentation.
 ### Code and validation
 
 - Native Linux/GCC build: zero errors and zero warnings.
-- Tests: 12,672 passing across 36 component binaries plus one integration
+- Tests: 12,675 passing across 36 component binaries plus one integration
   binary.
 - Component graph: 41 physical modules and 90 direct production edges.
 - Boundary validator: no cycles, duplicate public include paths, orphan
@@ -52,7 +52,7 @@ The 2026-07-25 local snapshot contains:
 | Table | State |
 |---|---|
 | `task` | 16,201 rows: 1,082 `ported`, 140 `ignore`, 14,979 legacy `ignored`; no unclassified or `tobedecided` rows |
-| `ticket` | 1,761 rows, all `done`; no `todo`, `doing`, `blocked`, or `needs_user` rows |
+| `ticket` | 1,762 rows, all `done`; no `todo`, `doing`, `blocked`, or `needs_user` rows |
 
 Because `plan.sqlite3` is git-ignored, these counts describe the maintainer
 snapshot, not data shipped in a fresh clone.
@@ -148,6 +148,9 @@ assertion without an explicit architecture decision.
   shifts over UTF-16BE units, optional-direct-character control, astral
   Unicode support, and U+FFFD recovery for malformed input. It remains
   obsolete and unsuitable for new protocols.
+- Added conditional `Trace::WriteIf` and `Trace::WriteLineIf` under ticket
+  #1762. They suppress output when false and retain the existing stderr
+  write/newline behavior when true.
 - Added consumer-driven coverage across core, collections, IO, networking,
   threading/tasks, text/JSON, XML, numerics, globalization, and cryptographic
   hashing/random APIs.
@@ -208,7 +211,7 @@ The first consumer-driven ports after modularization added:
 - XML schema exception types.
 
 The verified test baseline grew from 12,494 at the modularization checkpoint
-to 12,672.
+to 12,675.
 
 ## Candidate roadmap