diff --git a/ftplugin/todo.vim b/ftplugin/todo.vim
index 915002c..24584a1 100644
--- a/ftplugin/todo.vim
+++ b/ftplugin/todo.vim
@@ -9,6 +9,11 @@
 let s:save_cpo = &cpo
 set cpo&vim
 
+" Export Context Dictionary for unit testing {{{1
+function! todo#__context__()
+    return { 'sid': s:SID, 'scope': s: }
+endfunction
+
 " General options {{{1
 " Some options lose their values when window changes. They will be set every
 " time this script is invocated, which is whenever a file of this type is
diff --git a/test/tc_mark_as_done.todo.txt b/test/tc_mark_as_done.todo.txt
new file mode 100644
index 0000000..e706faf
--- /dev/null
+++ b/test/tc_mark_as_done.todo.txt
@@ -0,0 +1,5 @@
+# lorem_ipsum
+first task to be marked as done
+second task to be marked as done
+third task to be marked as done
+# end_lorem_ipsum
diff --git a/test/tc_mark_as_done.vim b/test/tc_mark_as_done.vim
new file mode 100644
index 0000000..f397df8
--- /dev/null
+++ b/test/tc_mark_as_done.vim
@@ -0,0 +1,36 @@
+let s:here = expand('<sfile>:p:h')
+let s:tc = unittest#testcase#new('Mask As Done', 
+      \ { 'data': s:here . '/tc_mark_as_done.todo.txt' })
+
+let s:LEADER = mapleader
+let s:TODAY = strftime("%Y-%m-%d")
+
+let s:FIRST_TASK_DONE = [
+      \ 'x ' . s:TODAY . ' first task to be marked as done',
+      \ 'second task to be marked as done',
+      \ 'third task to be marked as done',
+      \ ]
+
+let s:ALL_TASKS_DONE = [
+      \ 'x ' . s:TODAY . ' first task to be marked as done',
+      \ 'x ' . s:TODAY . ' second task to be marked as done',
+      \ 'x ' . s:TODAY . ' third task to be marked as done',
+      \ ]
+
+function! s:tc.test_mark_as_done()
+  call self.data.goto('lorem_ipsum')
+  execute 'normal ' . s:LEADER . 'x'
+  call self.assert_equal(s:FIRST_TASK_DONE, self.data.get('lorem_ipsum'))
+endfunction
+
+function! s:tc.test_mark_range_as_done()
+  call self.data.execute('normal ' . s:LEADER . 'x', 'lorem_ipsum')
+  call self.assert_equal(s:ALL_TASKS_DONE, self.data.get('lorem_ipsum'))
+endfunction
+
+function! s:tc.test_mark_selection_as_done()
+  call self.data.visual_execute('normal ' . s:LEADER . 'x', 'lorem_ipsum')
+  call self.assert_equal(s:ALL_TASKS_DONE, self.data.get('lorem_ipsum'))
+endfunction
+
+unlet s:tc
diff --git a/test/tc_sort_context.todo.txt b/test/tc_sort_context.todo.txt
new file mode 100644
index 0000000..c74e59a
--- /dev/null
+++ b/test/tc_sort_context.todo.txt
@@ -0,0 +1,3 @@
+(B) Linear regression Rnet=Qh@Qle. @cons_emp_model
+(B) Review key questions. @benchmarking
+(A) simple model first @cons_emp_model
diff --git a/test/tc_sort_context.vim b/test/tc_sort_context.vim
new file mode 100644
index 0000000..7a82c4e
--- /dev/null
+++ b/test/tc_sort_context.vim
@@ -0,0 +1,20 @@
+let s:here = expand('<sfile>:p:h')
+let s:tc = unittest#testcase#new('Sort Context', 
+      \ { 'data': s:here . '/tc_sort_context.todo.txt' })
+
+let s:LEADER = mapleader
+
+let s:SORTED_TASKS = [
+      \ '(B) Review key questions. @benchmarking',
+      \ '(B) Linear regression Rnet=Qh@Qle. @cons_emp_model',
+      \ '(A) simple model first @cons_emp_model',
+      \ ]
+
+function! s:tc.test_sort_by_context()
+  execute 'normal ' . s:LEADER . 's@'
+  execute 'normal ggO# lorem_ipsum'
+  execute 'normal Go# end_lorem_ipsum'
+  call self.assert_equal(s:SORTED_TASKS, self.data.get('lorem_ipsum'))
+endfunction
+
+unlet s:tc
diff --git a/test/tc_sort_project.todo.txt b/test/tc_sort_project.todo.txt
new file mode 100644
index 0000000..fbfc534
--- /dev/null
+++ b/test/tc_sort_project.todo.txt
@@ -0,0 +1,3 @@
+(B) Linear regression Rnet=Qh+Qle. +cons_emp_model
+(B) Review key questions. +benchmarking
+(A) simple model first +cons_emp_model
diff --git a/test/tc_sort_project.vim b/test/tc_sort_project.vim
new file mode 100644
index 0000000..ba71dd3
--- /dev/null
+++ b/test/tc_sort_project.vim
@@ -0,0 +1,20 @@
+let s:here = expand('<sfile>:p:h')
+let s:tc = unittest#testcase#new('Sort Project', 
+      \ { 'data': s:here . '/tc_sort_project.todo.txt' })
+
+let s:LEADER = mapleader
+
+let s:SORTED_TASKS = [
+      \ '(B) Review key questions. +benchmarking',
+      \ '(B) Linear regression Rnet=Qh+Qle. +cons_emp_model',
+      \ '(A) simple model first +cons_emp_model',
+      \ ]
+
+function! s:tc.test_sort_by_project()
+  execute 'normal ' . s:LEADER . 's+'
+  execute 'normal ggO# lorem_ipsum'
+  execute 'normal Go# end_lorem_ipsum'
+  call self.assert_equal(s:SORTED_TASKS, self.data.get('lorem_ipsum'))
+endfunction
+
+unlet s:tc