diff --git a/tests/mutator_spec.lua b/tests/mutator_spec.lua
index 55b9c0c..13349e2 100644
--- a/tests/mutator_spec.lua
+++ b/tests/mutator_spec.lua
@@ -2,259 +2,18 @@ require("plenary.async").tests.add_to_env()
 local cache = require("oil.cache")
 local constants = require("oil.constants")
 local mutator = require("oil.mutator")
-local parser = require("oil.mutator.parser")
 local test_adapter = require("oil.adapters.test")
 local test_util = require("tests.test_util")
-local util = require("oil.util")
-local view = require("oil.view")
 
 local FIELD_ID = constants.FIELD_ID
 local FIELD_NAME = constants.FIELD_NAME
 local FIELD_TYPE = constants.FIELD_TYPE
-local FIELD_META = constants.FIELD_META
-
-local function set_lines(bufnr, lines)
-  vim.bo[bufnr].modifiable = true
-  vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, lines)
-end
 
 a.describe("mutator", function()
   after_each(function()
-    for _, bufnr in ipairs(vim.api.nvim_list_bufs()) do
-      vim.api.nvim_buf_delete(bufnr, { force = true })
-    end
-    test_adapter.test_clear()
-    cache.clear_everything()
     test_util.reset_editor()
   end)
 
-  describe("parser", function()
-    it("detects new files", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "a.txt",
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({ { entry_type = "file", name = "a.txt", type = "new" } }, diffs)
-    end)
-
-    it("detects new directories", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "foo/",
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({ { entry_type = "directory", name = "foo", type = "new" } }, diffs)
-    end)
-
-    it("detects new links", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "a.txt -> b.txt",
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same(
-        { { entry_type = "link", name = "a.txt", type = "new", link = "b.txt" } },
-        diffs
-      )
-    end)
-
-    it("detects deleted files", function()
-      local file = test_adapter.test_set("/foo/a.txt", "file")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {})
-      local diffs = parser.parse(bufnr)
-      assert.are.same({
-        { name = "a.txt", type = "delete", id = file[FIELD_ID] },
-      }, diffs)
-    end)
-
-    it("detects deleted directories", function()
-      local dir = test_adapter.test_set("/foo/bar", "directory")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {})
-      local diffs = parser.parse(bufnr)
-      assert.are.same({
-        { name = "bar", type = "delete", id = dir[FIELD_ID] },
-      }, diffs)
-    end)
-
-    it("detects deleted links", function()
-      local file = test_adapter.test_set("/foo/a.txt", "link")
-      file[FIELD_META] = { link = "b.txt" }
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {})
-      local diffs = parser.parse(bufnr)
-      assert.are.same({
-        { name = "a.txt", type = "delete", id = file[FIELD_ID] },
-      }, diffs)
-    end)
-
-    it("ignores empty lines", function()
-      local file = test_adapter.test_set("/foo/a.txt", "file")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      local cols = view.format_entry_cols(file, {}, {}, test_adapter)
-      local lines = util.render_table({ cols }, {})
-      table.insert(lines, "")
-      table.insert(lines, "     ")
-      set_lines(bufnr, lines)
-      local diffs = parser.parse(bufnr)
-      assert.are.same({}, diffs)
-    end)
-
-    it("errors on missing filename", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "/008",
-      })
-      local _, errors = parser.parse(bufnr)
-      assert.are_same({
-        {
-          message = "Malformed ID at start of line",
-          lnum = 0,
-          col = 0,
-        },
-      }, errors)
-    end)
-
-    it("errors on empty dirname", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "/008 /",
-      })
-      local _, errors = parser.parse(bufnr)
-      assert.are.same({
-        {
-          message = "No filename found",
-          lnum = 0,
-          col = 0,
-        },
-      }, errors)
-    end)
-
-    it("errors on duplicate names", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "foo",
-        "foo/",
-      })
-      local _, errors = parser.parse(bufnr)
-      assert.are.same({
-        {
-          message = "Duplicate filename",
-          lnum = 1,
-          col = 0,
-        },
-      }, errors)
-    end)
-
-    it("errors on duplicate names for existing files", function()
-      local file = test_adapter.test_set("/foo/a.txt", "file")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "a.txt",
-        string.format("/%d a.txt", file[FIELD_ID]),
-      })
-      local _, errors = parser.parse(bufnr)
-      assert.are.same({
-        {
-          message = "Duplicate filename",
-          lnum = 1,
-          col = 0,
-        },
-      }, errors)
-    end)
-
-    it("ignores new dirs with empty name", function()
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        "/",
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({}, diffs)
-    end)
-
-    it("parses a rename as a delete + new", function()
-      local file = test_adapter.test_set("/foo/a.txt", "file")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        string.format("/%d b.txt", file[FIELD_ID]),
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({
-        { type = "new", id = file[FIELD_ID], name = "b.txt", entry_type = "file" },
-        { type = "delete", id = file[FIELD_ID], name = "a.txt" },
-      }, diffs)
-    end)
-
-    it("detects a new trailing slash as a delete + create", function()
-      local file = test_adapter.test_set("/foo", "file")
-      vim.cmd.edit({ args = { "oil-test:///" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        string.format("/%d foo/", file[FIELD_ID]),
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({
-        { type = "new", name = "foo", entry_type = "directory" },
-        { type = "delete", id = file[FIELD_ID], name = "foo" },
-      }, diffs)
-    end)
-
-    it("detects renamed files that conflict", function()
-      local afile = test_adapter.test_set("/foo/a.txt", "file")
-      local bfile = test_adapter.test_set("/foo/b.txt", "file")
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        string.format("/%d a.txt", bfile[FIELD_ID]),
-        string.format("/%d b.txt", afile[FIELD_ID]),
-      })
-      local diffs = parser.parse(bufnr)
-      local first_two = { diffs[1], diffs[2] }
-      local last_two = { diffs[3], diffs[4] }
-      table.sort(first_two, function(a, b)
-        return a.id < b.id
-      end)
-      table.sort(last_two, function(a, b)
-        return a.id < b.id
-      end)
-      assert.are.same({
-        { name = "b.txt", type = "new", id = afile[FIELD_ID], entry_type = "file" },
-        { name = "a.txt", type = "new", id = bfile[FIELD_ID], entry_type = "file" },
-      }, first_two)
-      assert.are.same({
-        { name = "a.txt", type = "delete", id = afile[FIELD_ID] },
-        { name = "b.txt", type = "delete", id = bfile[FIELD_ID] },
-      }, last_two)
-    end)
-
-    it("views link targets with trailing slashes as the same", function()
-      local file = test_adapter.test_set("/foo/mydir", "link")
-      file[FIELD_META] = { link = "dir/" }
-      vim.cmd.edit({ args = { "oil-test:///foo/" } })
-      local bufnr = vim.api.nvim_get_current_buf()
-      set_lines(bufnr, {
-        string.format("/%d mydir/ -> dir/", file[FIELD_ID]),
-      })
-      local diffs = parser.parse(bufnr)
-      assert.are.same({}, diffs)
-    end)
-  end)
-
   describe("build actions", function()
     it("empty diffs produce no actions", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
diff --git a/tests/parser_spec.lua b/tests/parser_spec.lua
new file mode 100644
index 0000000..f3a4262
--- /dev/null
+++ b/tests/parser_spec.lua
@@ -0,0 +1,245 @@
+require("plenary.async").tests.add_to_env()
+local constants = require("oil.constants")
+local parser = require("oil.mutator.parser")
+local test_adapter = require("oil.adapters.test")
+local test_util = require("tests.test_util")
+local util = require("oil.util")
+local view = require("oil.view")
+
+local FIELD_ID = constants.FIELD_ID
+local FIELD_META = constants.FIELD_META
+
+local function set_lines(bufnr, lines)
+  vim.bo[bufnr].modifiable = true
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, lines)
+end
+
+describe("parser", function()
+  after_each(function()
+    test_util.reset_editor()
+  end)
+  it("detects new files", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "a.txt",
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({ { entry_type = "file", name = "a.txt", type = "new" } }, diffs)
+  end)
+
+  it("detects new directories", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "foo/",
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({ { entry_type = "directory", name = "foo", type = "new" } }, diffs)
+  end)
+
+  it("detects new links", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "a.txt -> b.txt",
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same(
+      { { entry_type = "link", name = "a.txt", type = "new", link = "b.txt" } },
+      diffs
+    )
+  end)
+
+  it("detects deleted files", function()
+    local file = test_adapter.test_set("/foo/a.txt", "file")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {})
+    local diffs = parser.parse(bufnr)
+    assert.are.same({
+      { name = "a.txt", type = "delete", id = file[FIELD_ID] },
+    }, diffs)
+  end)
+
+  it("detects deleted directories", function()
+    local dir = test_adapter.test_set("/foo/bar", "directory")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {})
+    local diffs = parser.parse(bufnr)
+    assert.are.same({
+      { name = "bar", type = "delete", id = dir[FIELD_ID] },
+    }, diffs)
+  end)
+
+  it("detects deleted links", function()
+    local file = test_adapter.test_set("/foo/a.txt", "link")
+    file[FIELD_META] = { link = "b.txt" }
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {})
+    local diffs = parser.parse(bufnr)
+    assert.are.same({
+      { name = "a.txt", type = "delete", id = file[FIELD_ID] },
+    }, diffs)
+  end)
+
+  it("ignores empty lines", function()
+    local file = test_adapter.test_set("/foo/a.txt", "file")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    local cols = view.format_entry_cols(file, {}, {}, test_adapter)
+    local lines = util.render_table({ cols }, {})
+    table.insert(lines, "")
+    table.insert(lines, "     ")
+    set_lines(bufnr, lines)
+    local diffs = parser.parse(bufnr)
+    assert.are.same({}, diffs)
+  end)
+
+  it("errors on missing filename", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "/008",
+    })
+    local _, errors = parser.parse(bufnr)
+    assert.are_same({
+      {
+        message = "Malformed ID at start of line",
+        lnum = 0,
+        col = 0,
+      },
+    }, errors)
+  end)
+
+  it("errors on empty dirname", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "/008 /",
+    })
+    local _, errors = parser.parse(bufnr)
+    assert.are.same({
+      {
+        message = "No filename found",
+        lnum = 0,
+        col = 0,
+      },
+    }, errors)
+  end)
+
+  it("errors on duplicate names", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "foo",
+      "foo/",
+    })
+    local _, errors = parser.parse(bufnr)
+    assert.are.same({
+      {
+        message = "Duplicate filename",
+        lnum = 1,
+        col = 0,
+      },
+    }, errors)
+  end)
+
+  it("errors on duplicate names for existing files", function()
+    local file = test_adapter.test_set("/foo/a.txt", "file")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "a.txt",
+      string.format("/%d a.txt", file[FIELD_ID]),
+    })
+    local _, errors = parser.parse(bufnr)
+    assert.are.same({
+      {
+        message = "Duplicate filename",
+        lnum = 1,
+        col = 0,
+      },
+    }, errors)
+  end)
+
+  it("ignores new dirs with empty name", function()
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      "/",
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({}, diffs)
+  end)
+
+  it("parses a rename as a delete + new", function()
+    local file = test_adapter.test_set("/foo/a.txt", "file")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      string.format("/%d b.txt", file[FIELD_ID]),
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({
+      { type = "new", id = file[FIELD_ID], name = "b.txt", entry_type = "file" },
+      { type = "delete", id = file[FIELD_ID], name = "a.txt" },
+    }, diffs)
+  end)
+
+  it("detects a new trailing slash as a delete + create", function()
+    local file = test_adapter.test_set("/foo", "file")
+    vim.cmd.edit({ args = { "oil-test:///" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      string.format("/%d foo/", file[FIELD_ID]),
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({
+      { type = "new", name = "foo", entry_type = "directory" },
+      { type = "delete", id = file[FIELD_ID], name = "foo" },
+    }, diffs)
+  end)
+
+  it("detects renamed files that conflict", function()
+    local afile = test_adapter.test_set("/foo/a.txt", "file")
+    local bfile = test_adapter.test_set("/foo/b.txt", "file")
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      string.format("/%d a.txt", bfile[FIELD_ID]),
+      string.format("/%d b.txt", afile[FIELD_ID]),
+    })
+    local diffs = parser.parse(bufnr)
+    local first_two = { diffs[1], diffs[2] }
+    local last_two = { diffs[3], diffs[4] }
+    table.sort(first_two, function(a, b)
+      return a.id < b.id
+    end)
+    table.sort(last_two, function(a, b)
+      return a.id < b.id
+    end)
+    assert.are.same({
+      { name = "b.txt", type = "new", id = afile[FIELD_ID], entry_type = "file" },
+      { name = "a.txt", type = "new", id = bfile[FIELD_ID], entry_type = "file" },
+    }, first_two)
+    assert.are.same({
+      { name = "a.txt", type = "delete", id = afile[FIELD_ID] },
+      { name = "b.txt", type = "delete", id = bfile[FIELD_ID] },
+    }, last_two)
+  end)
+
+  it("views link targets with trailing slashes as the same", function()
+    local file = test_adapter.test_set("/foo/mydir", "link")
+    file[FIELD_META] = { link = "dir/" }
+    vim.cmd.edit({ args = { "oil-test:///foo/" } })
+    local bufnr = vim.api.nvim_get_current_buf()
+    set_lines(bufnr, {
+      string.format("/%d mydir/ -> dir/", file[FIELD_ID]),
+    })
+    local diffs = parser.parse(bufnr)
+    assert.are.same({}, diffs)
+  end)
+end)
diff --git a/tests/test_util.lua b/tests/test_util.lua
index 63c55ca..e2ab2aa 100644
--- a/tests/test_util.lua
+++ b/tests/test_util.lua
@@ -1,5 +1,6 @@
 require("plenary.async").tests.add_to_env()
 local cache = require("oil.cache")
+local test_adapter = require("oil.adapters.test")
 local M = {}
 
 M.reset_editor = function()
@@ -21,6 +22,7 @@ M.reset_editor = function()
     vim.api.nvim_buf_delete(bufnr, { force = true })
   end
   cache.clear_everything()
+  test_adapter.test_clear()
 end
 
 M.wait_for_autocmd = a.wrap(function(autocmd, cb)