Handle conflicts with missing terminating newline

rafikdraoui · rafikdraoui · commit 20acec2eba0f · 2025-03-16T19:08:34.000-03:00
Since v0.26.0, when Jujutsu encounters a missing terminating newline character in a conflict, it will add a comment to the conflict markers. The way we are handling this use case is by actually making the regular expressions for matching conflict markers less strict: we now only check that there are trailing comments, regardless of whether they are in a format that we expect or not. In theory, this could have the potential of matching lines that are not conflict markers, but I believe that this is not likely now that Jujutsu uses long conflict markers to disambiguate conflict markers from file content. References: - https://jj-vcs.github.io/jj/latest/conflicts/#conflicts-with-missing-terminating-newline - https://jj-vcs.github.io/jj/latest/conflicts/#long-conflict-markers
diff --git a/README.md b/README.md
@@ -70,6 +70,8 @@ It can be used to test if the merge tool can handle markers of length higher tha
 
 The fourth file is `multiple_conflicts.txt`, which contains two conflict sections.
 
+The fifth file is `missing_newline.txt`, which contains a conflict for which one side is missing a terminating newline character.
+
 ## Troubleshooting
 
 The plugin includes a health check to detect potential issues that would prevent it from functioning properly.
diff --git a/lua/jj-diffconflicts/init.lua b/lua/jj-diffconflicts/init.lua
@@ -112,14 +112,11 @@ h.get_patterns = function(jj_version, marker_length)
     }
   else
     return {
-      top = "^" .. marker.top .. " Conflict %d+ of %d+$",
-      bottom = "^" .. marker.bottom .. " Conflict %d+ of %d+ ends$",
+      top = "^" .. marker.top .. " .+$",
+      bottom = "^" .. marker.bottom .. " .+$",
       -- We need to double `marker.diff` to escape the `%` symbols
-      diff = "^"
-        .. marker.diff
-        .. marker.diff
-        .. " Changes from base ?#?%d* to side #%d+$",
-      snapshot = "^" .. marker.snapshot .. " Contents of side #%d+$",
+      diff = "^" .. marker.diff .. marker.diff .. " .+$",
+      snapshot = "^" .. marker.snapshot .. " .+$",
     }
   end
 end
diff --git a/scripts/make-conflicts.sh b/scripts/make-conflicts.sh
@@ -50,6 +50,7 @@ apple
 grape
 orange
 EOF
+printf "grape" >missing_newline.txt
 ${JJ} bookmark create -r @ base
 ${JJ} commit -m 'Initial revision'
 
@@ -90,6 +91,7 @@ apple
 grape
 blood orange
 EOF
+printf "grapefruit" >missing_newline.txt
 ${JJ} bookmark create -r @ left
 ${JJ} describe -m 'Fix syntax mistakes, eat grapefruit'
 
@@ -131,6 +133,7 @@ APPLE
 GRAPE
 ORANGE
 EOF
+printf "grape\n" >missing_newline.txt
 ${JJ} bookmark create -r @ right
 ${JJ} describe -m 'Fix syntax mistakes, ALL CAPS fruits'
 
diff --git a/tests/data/missing_newline_markers.txt b/tests/data/missing_newline_markers.txt
@@ -0,0 +1,7 @@
+<<<<<<< Conflict 1 of 1
++++++++ Contents of side #1 (no terminating newline)
+grapefruit
+%%%%%%% Changes from base to side #2 (adds terminating newline)
+-grape
++grape
+>>>>>>> Conflict 1 of 1 ends
diff --git a/tests/screenshots/missing_newline_ui b/tests/screenshots/missing_newline_ui
@@ -0,0 +1,51 @@
+--|---------|---------|---------|---------|---------|---------|---------|---------|
+01|  grape                                │  grapefruit                            
+02|~                                      │~                                       
+03|~                                      │~                                       
+04|~                                      │~                                       
+05|~                                      │~                                       
+06|~                                      │~                                       
+07|~                                      │~                                       
+08|~                                      │~                                       
+09|~                                      │~                                       
+10|~                                      │~                                       
+11|~                                      │~                                       
+12|~                                      │~                                       
+13|~                                      │~                                       
+14|~                                      │~                                       
+15|~                                      │~                                       
+16|~                                      │~                                       
+17|~                                      │~                                       
+18|~                                      │~                                       
+19|~                                      │~                                       
+20|~                                      │~                                       
+21|~                                      │~                                       
+22|~                                      │~                                       
+23|[No Name] [+]        1,1            All snapshot [RO]         1,1            All
+24|Resolve conflicts leftward then save. Use :cq to abort.                         
+
+--|---------|---------|---------|---------|---------|---------|---------|---------|
+01|00111111111111111111111111111111111111120011111333331111111111111111111111111111
+02|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+03|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+04|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+05|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+06|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+07|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+08|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+09|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+10|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+11|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+12|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+13|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+14|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+15|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+16|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+17|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+18|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+19|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+20|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+21|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+22|00000000000000000000000000000000000000020000000000000000000000000000000000000000
+23|44444444444444444444444444444444444444445555555555555555555555555555555555555555
+24|66666666666666666666666666666666666666666666666666666667777777777777777777777777
diff --git a/tests/test_internal.lua b/tests/test_internal.lua
@@ -168,6 +168,24 @@ T["extract_conflicts"]["handles multiple conflicts"] = function()
   }
   eq(conflict, expected)
 end
+T["extract_conflicts"]["handles conflicts with missing newline markers"] = function()
+  local lines = read_file("tests/data/missing_newline_markers.txt")
+  local conflict = jj.extract_conflicts(default_patterns, lines)
+  local expected = {
+    {
+      top = 1,
+      bottom = 7,
+      lines = {
+        "+++++++ Contents of side #1 (no terminating newline)",
+        "grapefruit",
+        "%%%%%%% Changes from base to side #2 (adds terminating newline)",
+        "-grape",
+        "+grape",
+      },
+    },
+  }
+  eq(conflict, expected)
+end
 T["extract_conflicts"]["handles conflict numbered higher than 10"] = function()
   local lines = {
     "<<<<<<< Conflict 11 of 12",
diff --git a/tests/test_jj_diffconflicts.lua b/tests/test_jj_diffconflicts.lua
@@ -14,6 +14,7 @@ local SCREENSHOT = {
   fruits = "tests/screenshots/fruits_ui",
   long_markers = "tests/screenshots/long_markers_ui",
   multiple_conflicts = "tests/screenshots/multiple_conflicts_ui",
+  missing_newline = "tests/screenshots/missing_newline_ui",
 }
 
 local T = MiniTest.new_set({
@@ -75,6 +76,11 @@ T["run"]["handles multiple conflicts"] = function()
   child.lua("jj.run(false, 7)")
   expect.reference_screenshot(child.get_screenshot(), SCREENSHOT.multiple_conflicts)
 end
+T["run"]["handles missing newlines conflicts"] = function()
+  set_lines(read_file("tests/data/missing_newline_markers.txt"))
+  child.lua("jj.run(false, 7)")
+  expect.reference_screenshot(child.get_screenshot(), SCREENSHOT.missing_newline)
+end
 
 T["history view"] = MiniTest.new_set()
 T["history view"]["displays UI"] = function()
