From ebfcaef2403c3965d1a55c1125a03cfc9bde98b4 Mon Sep 17 00:00:00 2001
From: Oscar Wallberg <oscar.wallberg@outlook.com>
Date: Fri, 8 May 2026 03:12:41 +0200
Subject: [PATCH] fix(git/status_view): scope dispatch to current tabpage +
 test cleanup

---
 .emmyrc.json                  |   5 +-
 lua/git/status_view.lua       |  29 +++++----
 test/git/cmd_test.lua         | 116 ++++++++++++++++++----------------
 test/git/helpers.lua          |  11 +++-
 test/git/repo_test.lua        |  66 ++++++++++---------
 test/git/status_view_test.lua | 107 ++++++++++++++++++-------------
 test/init.lua                 |  21 +++++-
 test/runner.lua               |  16 +++--
 8 files changed, 217 insertions(+), 154 deletions(-)

diff --git a/.emmyrc.json b/.emmyrc.json
index ad70c06..4a7ba3e 100644
--- a/.emmyrc.json
+++ b/.emmyrc.json
@@ -2,7 +2,7 @@
   "$schema": "https://raw.githubusercontent.com/EmmyLuaLs/emmylua-analyzer-rust/refs/heads/main/crates/emmylua_code_analysis/resources/schema.json",
   "runtime": {
     "version": "LuaJIT",
-    "requirePattern": ["lua/?.lua", "lua/?/init.lua"]
+    "requirePattern": ["?.lua", "?/init.lua", "lua/?.lua", "lua/?/init.lua"]
   },
   "diagnostics": {
     "disable": ["unnecessary-if", "preferred-local-alias", "redefined-local"]
@@ -23,8 +23,7 @@
       "~/.local/share/nvim/site/pack/core/opt/nvim-tree.lua",
       "~/.local/share/nvim/site/pack/core/opt/oil.nvim",
       "~/.local/share/nvim/site/pack/core/opt/outline.nvim",
-      "~/.local/share/nvim/site/pack/core/opt/blink.cmp",
-      "./test"
+      "~/.local/share/nvim/site/pack/core/opt/blink.cmp"
     ]
   }
 }
diff --git a/lua/git/status_view.lua b/lua/git/status_view.lua
index a1ad66c..0bec220 100644
--- a/lua/git/status_view.lua
+++ b/lua/git/status_view.lua
@@ -62,14 +62,23 @@ local function find_view()
     end
 end
 
+---@param win integer?
+---@return boolean
+local function valid_in_current_tab(win)
+    if not win or not vim.api.nvim_win_is_valid(win) then
+        return false
+    end
+    return vim.api.nvim_win_get_tabpage(win)
+        == vim.api.nvim_get_current_tabpage()
+end
+
 ---@param s ow.Git.StatusView.State
 ---@return integer?
 local function win_for(s)
-    local win = s.win
-    if win and vim.api.nvim_win_is_valid(win) then
-        return win
+    if valid_in_current_tab(s.win) then
+        return s.win
     end
-    win = find_view()
+    local win = find_view()
     s.win = win
     return win
 end
@@ -267,14 +276,10 @@ end
 ---@return integer? left
 ---@return integer? right
 local function adopt_diff_wins(s, status_win)
-    local left = s.diff_left_win
-    local right = s.diff_right_win
-    if left and not vim.api.nvim_win_is_valid(left) then
-        left = nil
-    end
-    if right and not vim.api.nvim_win_is_valid(right) then
-        right = nil
-    end
+    local left = valid_in_current_tab(s.diff_left_win) and s.diff_left_win
+        or nil
+    local right = valid_in_current_tab(s.diff_right_win) and s.diff_right_win
+        or nil
     if left and right then
         return left, right
     end
diff --git a/test/git/cmd_test.lua b/test/git/cmd_test.lua
index 6ba531d..95f134d 100644
--- a/test/git/cmd_test.lua
+++ b/test/git/cmd_test.lua
@@ -1,15 +1,13 @@
-local t = require("test")
-local helpers = require("test.git.helpers")
 local cmd = require("git.cmd")
+local h = require("test.git.helpers")
+local t = require("test")
 
 require("git").init()
 
-local git = helpers.git
-
 ---@param files table<string, string>?
 ---@return string dir
 local function make_repo(files)
-    return helpers.make_repo(files, { cd = true })
+    return h.make_repo(files, { cd = true })
 end
 
 ---@param actual string[]
@@ -49,12 +47,9 @@ t.test("parse_args handles escaped quote inside double quotes", function()
     t.eq(cmd.parse_args([["a\"b" c]]), { 'a"b', "c" })
 end)
 
-t.test(
-    "parse_args treats backslash literally inside single quotes",
-    function()
-        t.eq(cmd.parse_args([['a\b' c]]), { "a\\b", "c" })
-    end
-)
+t.test("parse_args treats backslash literally inside single quotes", function()
+    t.eq(cmd.parse_args([['a\b' c]]), { "a\\b", "c" })
+end)
 
 t.test("parse_args concatenates adjacent quoted segments", function()
     t.eq(cmd.parse_args([[foo"bar"baz]]), { "foobarbaz" })
@@ -162,19 +157,19 @@ end)
 
 t.test("complete branch returns plain refs (no pseudo, no stash)", function()
     local dir = make_repo({ a = "x" })
-    git(dir, "branch", "feature")
-    git(dir, "tag", "v1")
+    h.git(dir, "branch", "feature")
+    h.git(dir, "tag", "v1")
     t.write(dir, "a", "modified")
-    git(dir, "stash")
+    h.git(dir, "stash")
     local matches = cmd.complete("", "G branch ", 9)
     eq_sorted(matches, { "feature", "main", "v1" })
 end)
 
 t.test("complete merge returns refs + pseudo + stash", function()
     local dir = make_repo({ a = "x" })
-    git(dir, "branch", "feature")
+    h.git(dir, "branch", "feature")
     t.write(dir, "a", "y")
-    git(dir, "stash")
+    h.git(dir, "stash")
     local matches = cmd.complete("", "G merge ", 8)
     eq_sorted(
         matches,
@@ -184,15 +179,15 @@ end)
 
 t.test("complete push first positional returns remotes", function()
     local dir = make_repo({ a = "x" })
-    git(dir, "remote", "add", "origin", "/tmp/nope")
-    git(dir, "remote", "add", "upstream", "/tmp/nope")
+    h.git(dir, "remote", "add", "origin", "/tmp/nope")
+    h.git(dir, "remote", "add", "upstream", "/tmp/nope")
     local matches = cmd.complete("", "G push ", 7)
     eq_sorted(matches, { "origin", "upstream" })
 end)
 
 t.test("complete push second positional returns refs", function()
     local dir = make_repo({ a = "x" })
-    git(dir, "branch", "feature")
+    h.git(dir, "branch", "feature")
     local matches = cmd.complete("", "G push origin ", 14)
     eq_sorted(matches, { "HEAD", "feature", "main" })
 end)
@@ -203,9 +198,9 @@ t.test("complete add returns only unstaged/untracked paths", function()
     t.write(dir, "newfile", "new")
     local r = assert(require("git.repo").resolve(dir))
     r:refresh()
-    vim.wait(500, function()
+    t.wait_for(function()
         return r.status and #vim.tbl_keys(r.status.entries) > 0
-    end)
+    end, "git status to report entries", 500)
     local matches = cmd.complete("", "G add ", 6)
     eq_sorted(matches, { "newfile", "tracked" })
 end)
@@ -218,19 +213,19 @@ t.test("complete after `--` returns tracked paths only", function()
 end)
 
 t.test("complete stash returns subsubcommands", function()
-    local dir = make_repo({ a = "x" })
+    make_repo({ a = "x" })
     local matches = cmd.complete("p", "G stash p", 9)
     eq_sorted(matches, { "pop", "push" })
 end)
 
 t.test("complete show with <rev>:<path> returns tree paths", function()
-    local dir = make_repo({ a = "x", ["sub/b"] = "y" })
+    make_repo({ a = "x", ["sub/b"] = "y" })
     local matches = cmd.complete("HEAD:", "G show HEAD:", 12)
     eq_sorted(matches, { "HEAD:a", "HEAD:sub/" })
 end)
 
 t.test("complete unknown subcommand falls back to tracked paths", function()
-    local dir = make_repo({ a = "x", b = "y" })
+    make_repo({ a = "x", b = "y" })
     local matches = cmd.complete("", "G nonexistent ", 14)
     eq_sorted(matches, { "a", "b" })
 end)
@@ -250,14 +245,35 @@ end
 ---@param buf_name_pattern string
 ---@param timeout integer?
 local function wait_buf_populated(buf_name_pattern, timeout)
-    vim.wait(timeout or 1000, function()
+    t.wait_for(function()
         for _, b in ipairs(vim.api.nvim_list_bufs()) do
             if vim.api.nvim_buf_get_name(b):match(buf_name_pattern) then
                 return #vim.api.nvim_buf_get_lines(b, 0, -1, false) > 1
             end
         end
         return false
-    end)
+    end, "buffer matching " .. buf_name_pattern .. " to populate", timeout)
+end
+
+---Wait for a buffer matching `buf_name_pattern` to contain a line whose
+---content equals `line`. Useful for asserting that re-running a :G
+---command repopulated the buffer with new output.
+---@param buf_name_pattern string
+---@param line string
+---@param timeout integer?
+local function wait_buf_has_line(buf_name_pattern, line, timeout)
+    t.wait_for(function()
+        for _, b in ipairs(vim.api.nvim_list_bufs()) do
+            if vim.api.nvim_buf_get_name(b):match(buf_name_pattern) then
+                for _, l in ipairs(vim.api.nvim_buf_get_lines(b, 0, -1, false)) do
+                    if l == line then
+                        return true
+                    end
+                end
+            end
+        end
+        return false
+    end, "buffer " .. buf_name_pattern .. " to contain " .. line, timeout)
 end
 
 t.test("run :G diff reuses the same buffer across invocations", function()
@@ -265,17 +281,17 @@ t.test("run :G diff reuses the same buffer across invocations", function()
     t.write(dir, "a", "v2\n")
 
     cmd.run({ "diff" })
-    wait_buf_populated("%[Git diff%]")
-    local first_count = count_bufs_named("%[Git diff%]")
-    t.eq(first_count, 1)
+    wait_buf_has_line("%[Git diff%]", "+v2")
+    t.eq(count_bufs_named("%[Git diff%]"), 1)
 
     t.write(dir, "a", "v3\n")
     cmd.run({ "diff" })
-    vim.wait(300)
+    wait_buf_has_line("%[Git diff%]", "+v3")
     t.eq(count_bufs_named("%[Git diff%]"), 1, "second :G diff should reuse")
 
+    t.write(dir, "a", "v4\n")
     cmd.run({ "diff" })
-    vim.wait(300)
+    wait_buf_has_line("%[Git diff%]", "+v4")
     t.eq(count_bufs_named("%[Git diff%]"), 1, "third :G diff should reuse")
 end)
 
@@ -293,13 +309,14 @@ end
 t.test(":G show <CR> on + line opens the blob URI", function()
     local dir = make_repo({ a = "first\n" })
     t.write(dir, "a", "second\n")
-    git(dir, "add", "a")
-    git(dir, "commit", "-q", "-m", "second")
-    local r = assert(require("git.repo").resolve(dir))
-    local blob = vim.trim(git(dir, "rev-parse", "HEAD:a").stdout)
+    h.git(dir, "add", "a")
+    h.git(dir, "commit", "-q", "-m", "second")
+    assert(require("git.repo").resolve(dir))
+    local blob = h.git(dir, "rev-parse", "HEAD:a").stdout
 
     cmd.run({ "show", "HEAD" })
     wait_buf_populated("%[Git show HEAD%]")
+    ---@type integer?
     local diff_buf
     for _, b in ipairs(vim.api.nvim_list_bufs()) do
         if vim.api.nvim_buf_get_name(b):match("%[Git show HEAD%]") then
@@ -319,30 +336,23 @@ end)
 t.test("<leader>gl log buffer refills after jumping back", function()
     local dir = make_repo({ a = "v1\n" })
     t.write(dir, "a", "v2\n")
-    helpers.git(dir, "add", "a")
-    helpers.git(dir, "commit", "-q", "-m", "second")
+    h.git(dir, "add", "a")
+    h.git(dir, "commit", "-q", "-m", "second")
 
     require("git.log_view").open({ max_count = 1000 })
     wait_buf_populated("^gitlog://")
     local log_buf = vim.api.nvim_get_current_buf()
     local log_win = vim.api.nvim_get_current_win()
-    t.truthy(
-        vim.api.nvim_buf_get_name(log_buf):match("^gitlog://")
-    )
-    local initial_lines =
-        #vim.api.nvim_buf_get_lines(log_buf, 0, -1, false)
+    t.truthy(vim.api.nvim_buf_get_name(log_buf):match("^gitlog://"))
+    local initial_lines = #vim.api.nvim_buf_get_lines(log_buf, 0, -1, false)
     t.truthy(initial_lines >= 2)
 
     -- Step into a commit, then <C-o> back to the log.
     vim.api.nvim_win_set_cursor(log_win, { 1, 0 })
-    local cr =
-        vim.api.nvim_replace_termcodes("<CR>", true, false, true)
-    vim.api.nvim_feedkeys(cr, "x", false)
+    t.press("<CR>")
     t.truthy(vim.api.nvim_buf_get_name(0):match("^git://"))
 
-    local co =
-        vim.api.nvim_replace_termcodes("<C-o>", true, false, true)
-    vim.api.nvim_feedkeys(co, "x", false)
+    t.press("<C-o>")
     t.eq(vim.api.nvim_get_current_buf(), log_buf)
     t.eq(
         #vim.api.nvim_buf_get_lines(log_buf, 0, -1, false),
@@ -354,8 +364,8 @@ end)
 t.test("<CR> still dispatches after navigating away and back", function()
     local dir = make_repo({ a = "v1\n" })
     t.write(dir, "a", "v2\n")
-    helpers.git(dir, "add", "a")
-    helpers.git(dir, "commit", "-q", "-m", "second")
+    h.git(dir, "add", "a")
+    h.git(dir, "commit", "-q", "-m", "second")
 
     -- Open the HEAD commit object buffer. Its cat-file output includes a
     -- "parent <sha>" line we can navigate from.
@@ -376,8 +386,7 @@ t.test("<CR> still dispatches after navigating away and back", function()
     -- <C-o> back to first_obj_buf. With bufhidden=delete, vim re-reads the
     -- URI, which previously raced with BufDelete-driven unbind and left
     -- state cleared, so open_under_cursor returned false.
-    local co = vim.api.nvim_replace_termcodes("<C-o>", true, false, true)
-    vim.api.nvim_feedkeys(co, "x", false)
+    t.press("<C-o>")
     t.eq(vim.api.nvim_get_current_buf(), first_obj_buf)
     local tree_lnum = assert(find_line(first_obj_buf, "tree "))
     vim.api.nvim_win_set_cursor(first_obj_win, { tree_lnum, 0 })
@@ -390,10 +399,11 @@ end)
 t.test(":G diff <CR> on + line falls back to worktree file", function()
     local dir = make_repo({ a = "v1\n" })
     t.write(dir, "a", "v2\n")
-    local r = assert(require("git.repo").resolve(dir))
+    assert(require("git.repo").resolve(dir))
 
     cmd.run({ "diff" })
     wait_buf_populated("%[Git diff%]")
+    ---@type integer?
     local diff_buf
     for _, b in ipairs(vim.api.nvim_list_bufs()) do
         if vim.api.nvim_buf_get_name(b):match("%[Git diff%]") then
diff --git a/test/git/helpers.lua b/test/git/helpers.lua
index 0730671..f01a7c4 100644
--- a/test/git/helpers.lua
+++ b/test/git/helpers.lua
@@ -2,9 +2,11 @@ local t = require("test")
 
 local M = {}
 
+---@class test.git.SystemCompleted : vim.SystemCompleted
+---@field stdout string
+
 ---@param dir string
----@vararg string
----@return vim.SystemCompleted
+---@return test.git.SystemCompleted
 function M.git(dir, ...)
     local r = vim.system({ "git", ... }, { cwd = dir, text = true }):wait()
     if r.code ~= 0 then
@@ -17,6 +19,11 @@ function M.git(dir, ...)
             2
         )
     end
+    if r.stdout then
+        r.stdout = vim.trim(r.stdout)
+    else
+        r.stdout = ""
+    end
     return r
 end
 
diff --git a/test/git/repo_test.lua b/test/git/repo_test.lua
index 0479f28..191c4f4 100644
--- a/test/git/repo_test.lua
+++ b/test/git/repo_test.lua
@@ -1,24 +1,22 @@
+---@diagnostic disable: access-invisible
+local h = require("test.git.helpers")
 local t = require("test")
-local helpers = require("test.git.helpers")
 
 require("git").init()
 
-local git = helpers.git
-local make_repo = helpers.make_repo
-
 ---@param r ow.Git.Repo
 ---@param key string
 ---@param timeout integer?
 local function wait_cleared(r, key, timeout)
-    vim.wait(timeout or 2000, function()
+    t.wait_for(function()
         return r._cache[key] == nil
-    end)
+    end, key .. " cache to clear", timeout or 2000)
 end
 
 t.test("list_refs returns heads, tags, remotes (no HEAD)", function()
-    local dir = make_repo({ a = "x" })
-    git(dir, "branch", "feature")
-    git(dir, "tag", "v1")
+    local dir = h.make_repo({ a = "x" })
+    h.git(dir, "branch", "feature")
+    h.git(dir, "tag", "v1")
     local r = assert(require("git.repo").resolve(dir))
     local refs = r:list_refs()
     table.sort(refs)
@@ -26,13 +24,13 @@ t.test("list_refs returns heads, tags, remotes (no HEAD)", function()
 end)
 
 t.test("list_pseudo_refs always includes HEAD", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     t.eq(r:list_pseudo_refs(), { "HEAD" })
 end)
 
 t.test("list_pseudo_refs picks up MERGE_HEAD when present", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     t.write(dir .. "/.git", "MERGE_HEAD", "deadbeef\n")
     -- Bypass cache (file appeared after first scan).
@@ -43,15 +41,15 @@ t.test("list_pseudo_refs picks up MERGE_HEAD when present", function()
 end)
 
 t.test("list_stash_refs is empty when no stash", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     t.eq(r:list_stash_refs(), {})
 end)
 
 t.test("list_stash_refs lists stash + entries when stash exists", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     t.write(dir, "a", "modified")
-    git(dir, "stash")
+    h.git(dir, "stash")
     local r = assert(require("git.repo").resolve(dir))
     local refs = r:list_stash_refs()
     t.eq(#refs, 2)
@@ -60,7 +58,7 @@ t.test("list_stash_refs lists stash + entries when stash exists", function()
 end)
 
 t.test("get_cached memoizes by key", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     local calls = 0
     local v1 = r:get_cached("k", function()
@@ -76,23 +74,23 @@ t.test("get_cached memoizes by key", function()
 end)
 
 t.test("cache clears after top-level .git change (commit)", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     local _ = r:list_refs()
     t.truthy(r._cache.refs)
     t.write(dir, "b", "y")
-    git(dir, "add", "b")
-    git(dir, "commit", "-q", "-m", "two")
+    h.git(dir, "add", "b")
+    h.git(dir, "commit", "-q", "-m", "two")
     wait_cleared(r, "refs")
     t.falsy(r._cache.refs, "cache should be cleared after commit")
 end)
 
 t.test("cache clears after slash-branch creation (polyfill)", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     local _ = r:list_refs()
     t.truthy(r._cache.refs)
-    git(dir, "branch", "feat/foo")
+    h.git(dir, "branch", "feat/foo")
     wait_cleared(r, "refs")
     t.falsy(r._cache.refs, "cache should clear via polyfilled subdir watcher")
     local refs = r:list_refs()
@@ -101,10 +99,10 @@ t.test("cache clears after slash-branch creation (polyfill)", function()
 end)
 
 t.test("cache clears after deeply nested slash branch", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     local _ = r:list_refs()
-    git(dir, "branch", "deep/a/b/c")
+    h.git(dir, "branch", "deep/a/b/c")
     wait_cleared(r, "refs")
     local refs = r:list_refs()
     table.sort(refs)
@@ -112,9 +110,9 @@ t.test("cache clears after deeply nested slash branch", function()
 end)
 
 t.test("resolve_sha returns ok + full sha for a known blob", function()
-    local dir = make_repo({ a = "hello\n" })
+    local dir = h.make_repo({ a = "hello\n" })
     local r = assert(require("git.repo").resolve(dir))
-    local blob = vim.trim(git(dir, "rev-parse", "HEAD:a").stdout)
+    local blob = h.git(dir, "rev-parse", "HEAD:a").stdout
     local short = blob:sub(1, 7)
     local full, status = r:resolve_sha(short)
     t.eq(status, "ok")
@@ -122,7 +120,7 @@ t.test("resolve_sha returns ok + full sha for a known blob", function()
 end)
 
 t.test("resolve_sha returns missing for an unknown prefix", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
     local full, status = r:resolve_sha("0000deadbeef")
     t.eq(full, nil)
@@ -130,29 +128,29 @@ t.test("resolve_sha returns missing for an unknown prefix", function()
 end)
 
 t.test("resolve_sha caches by prefix", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
-    local blob = vim.trim(git(dir, "rev-parse", "HEAD:a").stdout)
+    local blob = h.git(dir, "rev-parse", "HEAD:a").stdout
     local short = blob:sub(1, 7)
     local _, _ = r:resolve_sha(short)
     t.truthy(r._cache["resolve:" .. short], "result should be cached")
 end)
 
 t.test("watcher cleans up after a slash-branch dir is removed", function()
-    local dir = make_repo({ a = "x" })
+    local dir = h.make_repo({ a = "x" })
     local r = assert(require("git.repo").resolve(dir))
-    git(dir, "branch", "feat/foo")
+    h.git(dir, "branch", "feat/foo")
     -- Wait for the dynamic watcher on .git/refs/heads/feat to be added.
     local feat_path = dir .. "/.git/refs/heads/feat"
-    vim.wait(2000, function()
+    t.wait_for(function()
         return r._watchers[feat_path] ~= nil
-    end)
+    end, "watcher to be installed on feat/ subdir", 2000)
     t.truthy(r._watchers[feat_path], "feat/ subdir should be watched")
     -- Remove the branch; the feat/ directory becomes empty and is
     -- pruned by git, triggering the deleted-self event.
-    git(dir, "branch", "-D", "feat/foo")
-    vim.wait(2000, function()
+    h.git(dir, "branch", "-D", "feat/foo")
+    t.wait_for(function()
         return r._watchers[feat_path] == nil
-    end)
+    end, "watcher on feat/ subdir to close", 2000)
     t.falsy(r._watchers[feat_path], "watcher should self-close")
 end)
diff --git a/test/git/status_view_test.lua b/test/git/status_view_test.lua
index bc1b933..7e7ecd1 100644
--- a/test/git/status_view_test.lua
+++ b/test/git/status_view_test.lua
@@ -1,11 +1,8 @@
+local h = require("test.git.helpers")
 local t = require("test")
-local helpers = require("test.git.helpers")
 
 require("git").init()
 
-local git = helpers.git
-local make_repo = helpers.make_repo
-
 ---Replicate the user's global cursor-restore autocmd. Scoped to a
 ---named augroup + cleanup so it doesn't leak between tests.
 local function install_cursor_restore_autocmd()
@@ -32,26 +29,24 @@ local function find_line(sidebar_buf, needle)
     end
 end
 
----@return integer? sidebar_buf, integer? sidebar_win
+---Find the gitstatus sidebar window in the current tabpage.
+---@return integer? sidebar_buf
+---@return integer? sidebar_win
 local function find_sidebar()
-    local buf, win
-    for _, b in ipairs(vim.api.nvim_list_bufs()) do
+    for _, w in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
+        local b = vim.api.nvim_win_get_buf(w)
         if vim.bo[b].filetype == "gitstatus" then
-            buf = b
+            return b, w
         end
     end
-    for _, w in ipairs(vim.api.nvim_list_wins()) do
-        if vim.api.nvim_win_get_buf(w) == buf then
-            win = w
-        end
-    end
-    return buf, win
 end
 
----@param role string
+---Find a diff-role window in the given tabpage (or current).
+---@param role "left"|"right"
+---@param tab integer?
 ---@return integer?
-local function find_diff_win(role)
-    for _, w in ipairs(vim.api.nvim_list_wins()) do
+local function find_diff_win(role, tab)
+    for _, w in ipairs(vim.api.nvim_tabpage_list_wins(tab or 0)) do
         if vim.w[w].git_diff_role == role then
             return w
         end
@@ -68,7 +63,7 @@ local function setup_sidebar_with_unstaged_file(
     committed_content,
     worktree_content
 )
-    local repo = make_repo({ [file_path] = committed_content })
+    local repo = h.make_repo({ [file_path] = committed_content })
     t.write(repo, file_path, worktree_content)
     vim.cmd("cd " .. repo)
 
@@ -82,9 +77,9 @@ local function setup_sidebar_with_unstaged_file(
         "repo should resolve for the test worktree"
     )
     r:refresh()
-    vim.wait(1000, function()
+    t.wait_for(function()
         return r.status and #r.status:by_kind("unstaged") > 0
-    end)
+    end, "git status to report unstaged changes")
 
     local entry_line = assert(
         find_line(sidebar_buf, vim.pesc(file_path) .. "$"),
@@ -93,17 +88,6 @@ local function setup_sidebar_with_unstaged_file(
     return sidebar_win, entry_line
 end
 
-local function press(keys)
-    local rhs = vim.api.nvim_replace_termcodes(keys, true, false, true)
-    vim.api.nvim_feedkeys(rhs, "x", false)
-end
-
----@param cond fun(): boolean
----@param msg string
-local function wait_for(cond, msg)
-    t.truthy(vim.wait(1000, cond), "timed out waiting for: " .. msg)
-end
-
 t.test("stage with diff open: sidebar cursor stays put", function()
     install_cursor_restore_autocmd()
     local sidebar_win, line = setup_sidebar_with_unstaged_file(
@@ -115,15 +99,15 @@ t.test("stage with diff open: sidebar cursor stays put", function()
     vim.api.nvim_set_current_win(sidebar_win)
     vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })
 
-    press("<Tab>")
-    wait_for(function()
+    t.press("<Tab>")
+    t.wait_for(function()
         return find_diff_win("left") ~= nil
     end, "diff windows to appear")
 
     local r = assert(require("git.repo").find(vim.fn.getcwd()))
     vim.api.nvim_set_current_win(sidebar_win)
-    press("s")
-    wait_for(function()
+    t.press("s")
+    t.wait_for(function()
         return #r.status:by_kind("staged") > 0
     end, "stage to propagate to repo state")
 
@@ -146,8 +130,8 @@ t.test(
         vim.api.nvim_set_current_win(sidebar_win)
         vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })
 
-        press("<Tab>")
-        wait_for(function()
+        t.press("<Tab>")
+        t.wait_for(function()
             return find_diff_win("left") ~= nil
         end, "diff windows to appear")
         local left_win = assert(find_diff_win("left"))
@@ -159,8 +143,8 @@ t.test(
 
         local r = assert(require("git.repo").find(vim.fn.getcwd()))
         vim.api.nvim_set_current_win(sidebar_win)
-        press("s")
-        wait_for(function()
+        t.press("s")
+        t.wait_for(function()
             return #r.status:by_kind("staged") > 0
         end, "stage to propagate to repo state")
 
@@ -172,14 +156,51 @@ t.test(
     end
 )
 
+t.test(
+    "<Tab> in a second tabpage opens the diff inside that tabpage",
+    function()
+        local sidebar_win, line =
+            setup_sidebar_with_unstaged_file("foo.txt", "v1\n", "v2\n")
+        local tab1 = vim.api.nvim_get_current_tabpage()
+
+        -- First show diff in tab1, so state.diff_*_win point at tab1.
+        vim.api.nvim_set_current_win(sidebar_win)
+        vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })
+        t.press("<Tab>")
+        t.wait_for(function()
+            return find_diff_win("left", tab1) ~= nil
+        end, "diff windows in tab1 to appear")
+
+        vim.cmd("tabnew")
+        require("git.status_view").open({ placement = "sidebar" })
+        local tab2 = vim.api.nvim_get_current_tabpage()
+        t.truthy(tab2 ~= tab1, "tabnew should produce a distinct tabpage")
+
+        local _, sidebar_win2 = find_sidebar()
+        assert(sidebar_win2, "sidebar window should exist in tab2")
+        vim.api.nvim_set_current_win(sidebar_win2)
+        vim.api.nvim_win_set_cursor(sidebar_win2, { line, 0 })
+
+        t.press("<Tab>")
+        t.wait_for(function()
+            return find_diff_win("left", tab2) ~= nil
+        end, "diff windows in tab2 to appear")
+
+        t.truthy(
+            find_diff_win("right", tab2),
+            "right diff window should be in tab2"
+        )
+    end
+)
+
 t.test("refresh on stage updates the index URI buffer's content", function()
     local sidebar_win, line =
         setup_sidebar_with_unstaged_file("foo.txt", "v1\n", "v2\n")
 
     vim.api.nvim_set_current_win(sidebar_win)
     vim.api.nvim_win_set_cursor(sidebar_win, { line, 0 })
-    press("<Tab>")
-    wait_for(function()
+    t.press("<Tab>")
+    t.wait_for(function()
         return find_diff_win("left") ~= nil
     end, "diff windows to appear")
 
@@ -192,8 +213,8 @@ t.test("refresh on stage updates the index URI buffer's content", function()
     )
 
     vim.api.nvim_set_current_win(sidebar_win)
-    press("s")
-    wait_for(function()
+    t.press("s")
+    t.wait_for(function()
         local first = vim.api.nvim_buf_get_lines(index_buf, 0, -1, false)[1]
         return first == "v2"
     end, "index pane to refresh to staged content")
diff --git a/test/init.lua b/test/init.lua
index 2708bc2..17c91b2 100644
--- a/test/init.lua
+++ b/test/init.lua
@@ -138,10 +138,27 @@ end
 ---@param content string
 function M.write(dir, path, content)
     local full = vim.fs.joinpath(dir, path)
-    vim.fn.mkdir(vim.fs.dirname(full), "p")
-    local f = assert(io.open(full --[[@as string]], "w"))
+    local parent = vim.fs.dirname(full)
+    vim.fn.mkdir(parent, "p")
+    local f, err = io.open(full, "w")
+    if not f then
+        error(err or "io.open failed: " .. full)
+    end
     f:write(content)
     f:close()
 end
 
+---@param keys string
+function M.press(keys)
+    local rhs = vim.api.nvim_replace_termcodes(keys, true, false, true)
+    vim.api.nvim_feedkeys(rhs, "x", false)
+end
+
+---@param cond fun(): boolean
+---@param msg string
+---@param timeout integer?
+function M.wait_for(cond, msg, timeout)
+    M.truthy(vim.wait(timeout or 1000, cond), "timed out waiting for: " .. msg)
+end
+
 return M
diff --git a/test/runner.lua b/test/runner.lua
index f2a3825..16b2b20 100644
--- a/test/runner.lua
+++ b/test/runner.lua
@@ -1,4 +1,7 @@
 local cfg = vim.fn.stdpath("config")
+if type(cfg) == "table" then
+    cfg = assert(cfg[1])
+end
 package.path = package.path
     .. (";" .. cfg .. "/lua/?.lua")
     .. (";" .. cfg .. "/lua/?/init.lua")
@@ -14,6 +17,8 @@ end
 
 local t = require("test")
 
+---@param target string
+---@return string[]?
 local function gather(target)
     local abs = vim.fn.fnamemodify(target, ":p")
     if vim.fn.isdirectory(abs) == 1 then
@@ -24,9 +29,8 @@ local function gather(target)
     end
 end
 
-local args = arg or {}
-local targets = #args > 0 and args or { cfg .. "/test" }
-
+local targets = (arg and #arg > 0) and arg or { cfg .. "/test" }
+---@type string[]
 local files = {}
 local resolve_failed = false
 for _, target in ipairs(targets) do
@@ -44,8 +48,10 @@ table.sort(files)
 
 local total_passed, total_failed = 0, 0
 for _, f in ipairs(files) do
-    f = f --[[@as string]]
-    local label = f:sub(1, #cfg + 1) == cfg .. "/" and f:sub(#cfg + 2) or f
+    local label = f
+    if f:sub(1, #cfg + 1) == cfg .. "/" then
+        label = f:sub(#cfg + 2)
+    end
     t.start_file(label)
     local ok, err = pcall(dofile, f)
     if not ok then