Fix buggy diff comments that were disappearing

Author: dglsparsons

AGENTS.md

@@ -42,6 +42,7 @@
 
 - Store `ReviewDiff` selector options (`target`, `--cached-only`, `--uncached-only`, `--merge-base`, `--tracked-only`) on the active local review so `ReviewSync` can re-run the same diff mode instead of silently falling back to default `diff`.
 - Do not carry `expanded_changes` extmark IDs across `ReviewSync`; extmarks are buffer-local and cleared by `state.clear_review()`, so stale IDs prevent old-code expansion from reapplying.
+- Local diff comments are state-only, so both reopened buffers and local `ReviewSync` need to repopulate overlays from `review.comments`; PR-only redraw paths make comments appear to vanish while navigation state is still intact.
 
 ## Learned while fixing PR comment pagination and LEFT-side rendering
 

lua/neo_reviewer/init.lua

@@ -900,10 +900,8 @@ function M.apply_overlay_to_buffer(bufnr)
     local signs = require("neo_reviewer.ui.signs")
     signs.place(bufnr, file.change_blocks)
 
-    if not state.is_local_review() then
-        local comments_ui = require("neo_reviewer.ui.comments")
-        comments_ui.show_existing(bufnr, file.path)
-    end
+    local comments_ui = require("neo_reviewer.ui.comments")
+    comments_ui.show_existing(bufnr, file.path)
 
     local buffer = require("neo_reviewer.ui.buffer")
     buffer.place_change_block_marks(bufnr, file)
@@ -1407,6 +1405,7 @@ function M.sync(opts)
             diff_opts = review.local_diff_opts or {},
             show_old_code = review.show_old_code,
             ai_analysis = review.ai_analysis,
+            comments = review.comments or {},
         }
         local ai_ui = require("neo_reviewer.ui.ai")
         local keep_ai_ui_open = ai_ui.is_open() and preserved.ai_analysis ~= nil
@@ -1456,6 +1455,22 @@ function M.sync(opts)
             new_review.show_old_code = preserved.show_old_code
             new_review.ai_analysis = preserved.ai_analysis
 
+            ---@type table<string, boolean>
+            local retained_paths = {}
+            for _, file in ipairs(filtered_files) do
+                retained_paths[file.path] = true
+            end
+
+            ---@type NRComment[]
+            local retained_comments = {}
+            -- Keep local notes only for files that still exist in the refreshed diff.
+            for _, comment in ipairs(preserved.comments) do
+                if retained_paths[comment.path] then
+                    table.insert(retained_comments, comment)
+                end
+            end
+            new_review.comments = retained_comments
+
             M.enable_overlay()
             if keep_ai_ui_open then
                 ai_ui.open({ preserve_layout = true })

lua/tests/plenary/init_review_diff_spec.lua

@@ -53,6 +53,7 @@ describe("neo_reviewer review noise filtering", function()
         package.loaded["neo_reviewer.ai"] = nil
         package.loaded["neo_reviewer.ui.ai"] = nil
         package.loaded["neo_reviewer.ui.nav"] = nil
+        package.loaded["neo_reviewer.ui.comments"] = nil
         state = require("neo_reviewer.state")
         cli = require("neo_reviewer.cli")
         config = require("neo_reviewer.config")
@@ -192,6 +193,57 @@ describe("neo_reviewer review noise filtering", function()
         assert.is_nil(find_loading_buffer())
     end)
 
+    it("re-renders local comments when a reviewed file buffer is reopened", function()
+        local repo_root = vim.fn.tempname()
+        vim.fn.mkdir(repo_root .. "/src", "p")
+        vim.fn.writefile({ "line 1", "line 2", "line 3" }, repo_root .. "/src/main.lua")
+        vim.fn.writefile({ "line 1", "line 2" }, repo_root .. "/src/other.lua")
+
+        state.set_local_review({
+            git_root = repo_root,
+            files = {
+                {
+                    path = "src/main.lua",
+                    status = "modified",
+                    change_blocks = {},
+                },
+                {
+                    path = "src/other.lua",
+                    status = "modified",
+                    change_blocks = {},
+                },
+            },
+        })
+
+        state.add_comment({
+            id = 7,
+            path = "src/main.lua",
+            line = 2,
+            side = "RIGHT",
+            body = "keep this comment",
+            author = "you",
+            created_at = "2025-01-01T00:00:00Z",
+        })
+
+        vim.cmd("edit " .. vim.fn.fnameescape(repo_root .. "/src/main.lua"))
+        local first_main = vim.api.nvim_get_current_buf()
+        neo_reviewer.apply_overlay_to_buffer(first_main)
+        assert.is_true(#helpers.get_extmarks(first_main, "nr_comments") > 0)
+
+        vim.cmd("edit " .. vim.fn.fnameescape(repo_root .. "/src/other.lua"))
+        local other = vim.api.nvim_get_current_buf()
+        neo_reviewer.apply_overlay_to_buffer(other)
+
+        vim.api.nvim_buf_delete(first_main, { force = true })
+
+        vim.cmd("edit " .. vim.fn.fnameescape(repo_root .. "/src/main.lua"))
+        local reopened_main = vim.api.nvim_get_current_buf()
+        neo_reviewer.apply_overlay_to_buffer(reopened_main)
+
+        local extmarks = helpers.get_extmarks(reopened_main, "nr_comments")
+        assert.is_true(#extmarks > 0)
+    end)
+
     it("skips default noise files in PR reviews", function()
         cli.fetch_pr = function(_, callback)
             callback(

lua/tests/plenary/sync_spec.lua

@@ -201,6 +201,49 @@ describe("neo_reviewer.sync", function()
             assert.are.same(analysis, state.get_ai_analysis())
         end)
 
+        it("preserves local comments for files that remain in the synced diff", function()
+            state.set_local_review(mock_data.local_diff, {
+                target = "main",
+            })
+            state.add_comment({
+                id = 77,
+                path = "src/main.lua",
+                line = 2,
+                side = "RIGHT",
+                body = "keep me",
+                author = "you",
+                created_at = "2025-01-01T00:00:00Z",
+            })
+            state.add_comment({
+                id = 78,
+                path = "src/removed.lua",
+                line = 1,
+                side = "RIGHT",
+                body = "drop me",
+                author = "you",
+                created_at = "2025-01-01T00:00:00Z",
+            })
+
+            cli.get_local_diff.invokes(function(_, callback)
+                callback({
+                    git_root = "/tmp/test",
+                    files = {
+                        { path = "src/main.lua", status = "modified", change_blocks = {} },
+                    },
+                }, nil)
+            end)
+
+            neo_reviewer.sync()
+
+            local review = state.get_review()
+            assert.is_not_nil(review)
+            if review then
+                assert.are.equal(1, #review.comments)
+                assert.are.equal(77, review.comments[1].id)
+                assert.are.equal("keep me", review.comments[1].body)
+            end
+        end)
+
         it("notifies user when local diff sync is in progress", function()
             state.set_local_review(mock_data.local_diff)