don't merge adjacent segments in combineOverlappingSegments

closes #2896

src/renderer/src/__snapshots__/segments.test.ts.snap

@@ -1,7 +1,53 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
-exports[`combineOverlappingSegments 1`] = `
+exports[`combineOverlappingSegments > adjacent 1`] = `
 [
+  {
+    "end": 2,
+    "start": 1,
+  },
+  {
+    "end": 3,
+    "start": 2,
+  },
+  {
+    "end": 4,
+    "start": 3,
+  },
+]
+`;
+
+exports[`combineOverlappingSegments > non touching 1`] = `
+[
+  {
+    "end": 2,
+    "start": 1,
+  },
+  {
+    "end": 4,
+    "start": 3,
+  },
+]
+`;
+
+exports[`combineOverlappingSegments > overlapping and non overlapping 1`] = `
+[
+  {
+    "end": 3,
+    "start": 1,
+  },
+  {
+    "end": 5,
+    "start": 4,
+  },
+]
+`;
+
+exports[`combineOverlappingSegments > various 1`] = `
+[
+  {
+    "start": 0,
+  },
   {
     "end": 87,
     "start": 0,
@@ -11,9 +57,16 @@ exports[`combineOverlappingSegments 1`] = `
     "start": 229,
   },
   {
-    "end": 1487,
+    "end": 1101,
     "start": 838,
   },
+  {
+    "end": 1487,
+    "start": 1101,
+  },
+  {
+    "start": 1487,
+  },
   {
     "end": 1831,
     "start": 1561,

src/renderer/src/segments.test.ts

@@ -101,57 +101,6 @@ it('detects overlapping segments', () => {
   ]);
 });
 
-test('combineOverlappingSegments', () => {
-  const segments = [
-    {
-      start: 0,
-    },
-    {
-      start: 838,
-      end: 1101,
-    },
-    {
-      start: 1101,
-      end: 1244,
-    },
-    {
-      start: 1216,
-      end: 1487,
-    },
-    {
-      start: 1487,
-    },
-    {
-      start: 1625,
-    },
-    {
-      start: 503,
-      end: 669,
-    },
-    {
-      start: 392,
-      end: 716,
-    },
-    {
-      start: 229,
-      end: 784,
-    },
-    {
-      start: 0,
-      end: 87,
-    },
-    {
-      start: 1561,
-      end: 1831,
-    },
-    {
-      start: 2027,
-    },
-  ];
-
-  expect(combineOverlappingSegments(segments)).toMatchSnapshot();
-});
-
 it('detects overlapping segments, undefined end', () => {
   expect(partitionIntoOverlappingRanges([
     { start: 1, end: undefined },
@@ -213,3 +162,77 @@ describe('invertSegments', () => {
     ], false, false)).toMatchSnapshot();
   });
 });
+
+describe('combineOverlappingSegments', () => {
+  test('non touching', () => {
+    expect(combineOverlappingSegments([
+      { start: 1, end: 2 },
+      { start: 3, end: 4 },
+    ])).toMatchSnapshot();
+  });
+  test('overlapping and non overlapping', () => {
+    expect(combineOverlappingSegments([
+      { start: 1, end: 2 },
+      { start: 1.5, end: 3 },
+      { start: 4, end: 5 },
+    ])).toMatchSnapshot();
+  });
+  test('adjacent', () => {
+    expect(combineOverlappingSegments([
+      { start: 1, end: 2 },
+      { start: 2, end: 3 },
+      { start: 3, end: 4 },
+    ])).toMatchSnapshot();
+  });
+
+  test('various', () => {
+    const segments = [
+      {
+        start: 0,
+      },
+      {
+        start: 838,
+        end: 1101,
+      },
+      {
+        start: 1101,
+        end: 1244,
+      },
+      {
+        start: 1216,
+        end: 1487,
+      },
+      {
+        start: 1487,
+      },
+      {
+        start: 1625,
+      },
+      {
+        start: 503,
+        end: 669,
+      },
+      {
+        start: 392,
+        end: 716,
+      },
+      {
+        start: 229,
+        end: 784,
+      },
+      {
+        start: 0,
+        end: 87,
+      },
+      {
+        start: 1561,
+        end: 1831,
+      },
+      {
+        start: 2027,
+      },
+    ];
+
+    expect(combineOverlappingSegments(segments)).toMatchSnapshot();
+  });
+});

src/renderer/src/segments.ts

@@ -129,8 +129,8 @@ export function combineOverlappingSegments<T extends SegmentBase>(existingSegmen
 
     const currentSegmentEndOrStart = currentSegment.end ?? currentSegment.start;
 
-    // Check if the current segment overlaps or is adjacent to the next segment
-    if (currentSegmentEndOrStart >= nextSegment.start) {
+    // Check if the current segment overlaps with the next segment
+    if (currentSegmentEndOrStart > nextSegment.start) {
       currentSegment = {
         ...currentSegment,
         end: Math.max(currentSegmentEndOrStart, nextSegment.end ?? nextSegment.start),