fix: collapsed items section not removed when empty

Author: josdejong

src/lib/logic/documentState.test.ts

@@ -388,7 +388,7 @@ describe('documentState', () => {
       const documentState: DocumentState = {
         ...createDocumentState({ json, expand: () => true }),
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 2 }]
+          '/members': [{ start: 0, end: 3 }]
         }
       }
 
@@ -463,7 +463,7 @@ describe('documentState', () => {
           '/members/3': true
         },
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 3 }]
+          '/members': [{ start: 0, end: 4 }]
         }
       })
     })
@@ -492,7 +492,7 @@ describe('documentState', () => {
           '': true
         },
         visibleSectionsMap: {
-          '': [{ start: 0, end: 4 }]
+          '': [{ start: 0, end: 5 }]
         }
       }
 
@@ -501,7 +501,7 @@ describe('documentState', () => {
       assert.deepStrictEqual(res.documentState, {
         ...documentState,
         visibleSectionsMap: {
-          '': [{ start: 0, end: 5 }]
+          '': [{ start: 0, end: 6 }]
         }
       })
     })
@@ -548,7 +548,7 @@ describe('documentState', () => {
         ...documentState,
         expandedMap: deleteIn(documentState.expandedMap, ['/members/2']), // [2] is moved to [1]
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 1 }]
+          '/members': [{ start: 0, end: 2 }]
         }
       })
     })
@@ -565,7 +565,7 @@ describe('documentState', () => {
         ...documentState,
         expandedMap: deleteIn(documentState.expandedMap, ['/members/2']), // [2] is moved to [1]
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 1 }]
+          '/members': [{ start: 0, end: 2 }]
         }
       })
     })
@@ -722,7 +722,7 @@ describe('documentState', () => {
           '/members/3': true
         },
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 3 }]
+          '/members': [{ start: 0, end: 4 }]
         }
       })
     })
@@ -871,7 +871,7 @@ describe('documentState', () => {
           '/members/3': true
         },
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 3 }]
+          '/members': [{ start: 0, end: 4 }]
         }
       })
     })
@@ -907,7 +907,7 @@ describe('documentState', () => {
           '/members/1': true
         },
         visibleSectionsMap: {
-          '/members': [{ start: 0, end: 1 }]
+          '/members': [{ start: 0, end: 2 }]
         }
       })
     })
@@ -940,7 +940,7 @@ describe('documentState', () => {
 
     test('should insert at the end of a visible section', () => {
       assert.deepStrictEqual(shiftVisibleSections(visibleSections, 2, 1), [
-        { start: 0, end: 3 },
+        { start: 0, end: 2 },
         { start: 5, end: 7 }
       ])
     })
@@ -959,12 +959,37 @@ describe('documentState', () => {
       ])
     })
 
-    test('should remove at the end of a visible section', () => {
+    test('should remove inside an invisible section (start)', () => {
       assert.deepStrictEqual(shiftVisibleSections(visibleSections, 2, -1), [
-        { start: 0, end: 1 },
+        { start: 0, end: 2 },
         { start: 3, end: 5 }
       ])
     })
+
+    test('should remove inside an invisible section (middle)', () => {
+      assert.deepStrictEqual(shiftVisibleSections(visibleSections, 3, -1), [
+        { start: 0, end: 2 },
+        { start: 3, end: 5 }
+      ])
+    })
+
+    test('should remove inside an invisible section (end)', () => {
+      assert.deepStrictEqual(shiftVisibleSections(visibleSections, 4, -1), [
+        { start: 0, end: 2 },
+        { start: 4, end: 5 }
+      ])
+    })
+
+    test('should merge visible sections when adjacent', () => {
+      const visibleSections2 = [
+        { start: 0, end: 100 },
+        { start: 200, end: 300 }
+      ]
+
+      assert.deepStrictEqual(shiftVisibleSections(visibleSections2, 100, -100), [
+        { start: 0, end: 200 }
+      ])
+    })
   })
 
   describe('expandPath', () => {

src/lib/logic/documentState.ts

@@ -648,12 +648,33 @@ export function shiftVisibleSections(
   index: number,
   offset: number
 ): VisibleSection[] {
-  return visibleSections.map((section) => {
+  const shiftedSections = visibleSections.map((section) => {
     return {
       start: section.start > index ? section.start + offset : section.start,
-      end: section.end >= index ? section.end + offset : section.end
+      end: section.end > index ? section.end + offset : section.end
     }
   })
+
+  return mergeAdjacentSections(shiftedSections)
+}
+
+// merge adjacent sections like [{start:0, end:100}, {start:100, end:200}] into [{start:0, end:200}]
+function mergeAdjacentSections(visibleSections: VisibleSection[]): VisibleSection[] {
+  const merged = visibleSections.slice(0)
+
+  let i = 1
+  while (i < merged.length) {
+    if (merged[i - 1].end === merged[i].start) {
+      merged[i - 1] = {
+        start: merged[i - 1].start,
+        end: merged[i].end
+      }
+      merged.splice(i)
+    }
+    i++
+  }
+
+  return merged
 }
 
 export function getEnforceString(