Render in place: a track's output to a new sibling, source to the bench

tests/test_capture_paths.cpp

@@ -362,6 +362,39 @@ static void testBankRelativeForNameMatchesDerivePathSpelling() {
     CHECK(bankRelativeForName(p.fileName) == p.relativePath);
 }
 
+// --- deriveRenderPaths ------------------------------------------------------
+
+static void testRenderPathsSpellTheStemExactlyAsTheBankPathDoes() {
+    // The one owner claim, made checkable: for the same baseName + uniqueTag, the
+    // bank path's stem and file name must BE the render path's. If these ever
+    // diverge, bankRelativeForName's exact-string match against an enumerated
+    // folder entry starts misfiring and prune misreads referenced files as orphans.
+    const BankPaths  bank   = deriveBankPaths("/proj", "kick drum!", "001");
+    const RenderPaths render = deriveRenderPaths("/proj/reasampler_bank",
+                                                 "kick drum!", "001");
+    CHECK(render.fileStem == bank.fileStem);
+    CHECK(render.fileName == bank.fileName);
+    CHECK(render.absoluteDir == bank.absoluteDir);
+}
+
+static void testRenderPathsTakeTheirDirectoryVerbatim() {
+    // No bank subfolder is appended — a render outside the bank has none, which is
+    // what makes "write into the bank folder" inexpressible through this call.
+    const RenderPaths r = deriveRenderPaths("/proj/media/", "take", "");
+    CHECK(r.absoluteDir == normalizeSlashes("/proj/media"));
+    CHECK(r.fileName == "take.wav");
+    CHECK(r.fileStem == "take");
+    // Backslashes normalize and a trailing slash is stripped, same as everywhere.
+    CHECK(deriveRenderPaths("C:\\proj\\media\\", "take", "").absoluteDir ==
+          normalizeSlashes("C:/proj/media"));
+}
+
+static void testRenderPathsEmptyDirectoryStaysEmpty() {
+    // No CWD fallback: an unresolvable directory must fail at the caller's own
+    // guard, never silently render next to whatever the process happened to be in.
+    CHECK(deriveRenderPaths("", "take", "001").absoluteDir.empty());
+}
+
 static void testBankRelativeForNameConventionAndEdge() {
     // The convention verbatim: "reasampler_bank/<name>" (the one place the spelling lives).
     CHECK(bankRelativeForName("a.wav") == "reasampler_bank/a.wav");
@@ -396,6 +429,9 @@ int main() {
     testTransitionFirstSaveOfUnsavedRelocatesButPlanNoOps();
     testTransitionInPlaceSaveIsNoOp();
     testBankRelativeForNameMatchesDerivePathSpelling();
+    testRenderPathsSpellTheStemExactlyAsTheBankPathDoes();
+    testRenderPathsTakeTheirDirectoryVerbatim();
+    testRenderPathsEmptyDirectoryStaysEmpty();
     testBankRelativeForNameConventionAndEdge();
 
     if (g_fail == 0) std::printf("capture_paths: all tests passed\n");