Make resurrect async…

package.json

@@ -33,7 +33,7 @@
   },
   "dependencies": {
     "@pulsar-edit/pathwatcher": "^9.0.4",
-    "@pulsar-edit/superstring": "^3.0.4",
+    "@pulsar-edit/superstring": "^3.0.8",
     "delegato": "^1.0.0",
     "diff": "^2.2.1",
     "event-kit": "^2.4.0",

spec/text-buffer-io-spec.js

@@ -785,17 +785,78 @@ describe('TextBuffer IO', () => {
           // Nothing was reloaded: the whole point of this scenario is that the
           // buffer's uncommitted changes are preserved.
           expect(reloadedCount).toBe(0)
-          expect(conflictedCount).toBe(1)
 
-          // The buffer stays conflicted; the status must not flip back on its
-          // own once the load finishes.
-          expect(conflictedStatusChanges).toEqual([true])
-          expect(buffer.isInConflict()).toBe(true)
+          // The file came back with exactly the contents our changes are
+          // based on, so there's nothing to conflict with.
+          expect(conflictedCount).toBe(0)
+          expect(conflictedStatusChanges).toEqual([])
+          expect(buffer.isInConflict()).toBe(false)
 
           expect(buffer.isDeleted()).toBe(false)
           expect(buffer.isModified()).toBe(true)
         })
 
+        describe('while the buffer has unsaved changes', () => {
+          async function deleteAndResurrect (restoredText) {
+            fs.unlinkSync(filePath)
+            await wait(500)
+            expect(buffer.isDeleted()).toBe(true)
+
+            const events = {conflictedCount: 0, conflictedStatusChanges: []}
+            buffer.onDidConflict(() => events.conflictedCount++)
+            buffer.onDidChangeConflicted((status) => events.conflictedStatusChanges.push(status))
+            fs.writeFileSync(filePath, restoredText)
+            await buffer.resurrect()
+            return events
+          }
+
+          beforeEach(async () => {
+            buffer.setText(`lorem ipsum`)
+            await buffer.save()
+            buffer.setText(`lorem ipsum dolor`)
+          })
+
+          it('reports a conflict if the file is restored with different contents', async () => {
+            const events = await deleteAndResurrect(`dolor sit amet`)
+            expect(events.conflictedCount).toBe(1)
+            expect(buffer.isInConflict()).toBe(true)
+            expect(buffer.isModified()).toBe(true)
+            expect(buffer.isDeleted()).toBe(false)
+            expect(buffer.getText()).toBe(`lorem ipsum dolor`)
+          })
+
+          it('reports a conflict if the file is restored empty', async () => {
+            const events = await deleteAndResurrect(``)
+            expect(events.conflictedCount).toBe(1)
+            expect(buffer.isInConflict()).toBe(true)
+            expect(buffer.getText()).toBe(`lorem ipsum dolor`)
+          })
+
+          it('does not report a conflict if the file is restored with the contents it had before', async () => {
+            const events = await deleteAndResurrect(`lorem ipsum`)
+            expect(events.conflictedCount).toBe(0)
+            expect(events.conflictedStatusChanges).toEqual([])
+            expect(buffer.isInConflict()).toBe(false)
+            expect(buffer.isModified()).toBe(true)
+            expect(buffer.isDeleted()).toBe(false)
+            expect(buffer.getText()).toBe(`lorem ipsum dolor`)
+          })
+
+          it('stays in conflict if it was already in conflict before the file was deleted', async () => {
+            const conflicted = new Promise((resolve) => buffer.onDidConflict(resolve))
+            fs.writeFileSync(filePath, `dolor sit amet`)
+            await conflicted
+            expect(buffer.isInConflict()).toBe(true)
+
+            // Even a file restored with the buffer's base text doesn't resolve
+            // a conflict that predates the deletion.
+            await deleteAndResurrect(`lorem ipsum`)
+            expect(buffer.isInConflict()).toBe(true)
+            expect(buffer.isModified()).toBe(true)
+            expect(buffer.isDeleted()).toBe(false)
+          })
+        })
+
         describe('and re-saved', () => {
           it('results in isModified and isDeleted no longer returning true', async () => {
             buffer.setText(`lorem ipsum`)

src/text-buffer.js

@@ -2085,7 +2085,7 @@ class TextBuffer {
   // Instead, this method exists as an easy way for an external file-watcher to
   // signal to `TextBuffer` that this buffer's backing file has been
   // resurrected, and that certain events ought to be emitted.
-  resurrect () {
+  async resurrect () {
     // Either the file came back but was gone again by the time we ran… or
     // something is calling this method speculatively (perhaps via polling) in
     // lieu of a file-watcher.
@@ -2098,6 +2098,25 @@ class TextBuffer {
     this.subscribeToFile()
 
     this.emitDeletedStatusChanged(false)
+
+    // A modified buffer won't reload, and a refused load is recorded as a
+    // conflict. That's correct only if the file came back with different
+    // contents than what our changes are based on — or if we were already in
+    // conflict before the file was deleted.
+    if (this.buffer.isModified() && !this.fileHasChangedSinceLastLoad) {
+      const source = this.file instanceof File
+        ? this.file.getPath()
+        : this.file.createReadStream()
+      let matches = false
+      try {
+        matches = await this.buffer.baseTextMatchesFile(source, this.getEncoding())
+      } catch (error) {
+        // If the file vanished again, `load` will handle it.
+        if (error.code !== 'ENOENT') throw error
+      }
+      if (matches) return
+    }
+
     // This is like calling `reload`, but less aggressive; it will preserve
     // uncommitted buffer contents and emit a `did-conflict` event instead of
     // clobbering those changes.