add

python/examples/pytest/test_fixture.out

@@ -1,14 +1,14 @@
-setup_module: <TemporaryDirectory '/tmp/tmp18kxxqva'>
-  setup_function <TemporaryDirectory '/tmp/tmp_bd8lazj'>
-    test_one <TemporaryDirectory '/tmp/tmp18kxxqva'> <TemporaryDirectory '/tmp/tmp_bd8lazj'>
+setup_module:         <TemporaryDirectory '/tmp/tmpaq1r7lnj'>
+  setup_function                                              <TemporaryDirectory '/tmp/tmpvynb1e5h'>
+    test_one          <TemporaryDirectory '/tmp/tmpaq1r7lnj'> <TemporaryDirectory '/tmp/tmpvynb1e5h'>
     test_one after
-  teardown_function <TemporaryDirectory '/tmp/tmp_bd8lazj'>
-  setup_function <TemporaryDirectory '/tmp/tmp9k2cbqcb'>
-    test_two <TemporaryDirectory '/tmp/tmp18kxxqva'> <TemporaryDirectory '/tmp/tmp9k2cbqcb'>
-  teardown_function <TemporaryDirectory '/tmp/tmp9k2cbqcb'>
-  setup_function <TemporaryDirectory '/tmp/tmp5u8n90cx'>
-    test_three <TemporaryDirectory '/tmp/tmp18kxxqva'> <TemporaryDirectory '/tmp/tmp5u8n90cx'>
+  teardown_function                                           <TemporaryDirectory '/tmp/tmpvynb1e5h'>
+  setup_function                                              <TemporaryDirectory '/tmp/tmp6cman2br'>
+    test_two          <TemporaryDirectory '/tmp/tmpaq1r7lnj'> <TemporaryDirectory '/tmp/tmp6cman2br'>
+  teardown_function                                           <TemporaryDirectory '/tmp/tmp6cman2br'>
+  setup_function                                              <TemporaryDirectory '/tmp/tmpbi9pwo3j'>
+    test_three        <TemporaryDirectory '/tmp/tmpaq1r7lnj'> <TemporaryDirectory '/tmp/tmpbi9pwo3j'>
     test_three after
-  teardown_function <TemporaryDirectory '/tmp/tmp5u8n90cx'>
-teardown_module <TemporaryDirectory '/tmp/tmp18kxxqva'>
+.  teardown_function                                          <TemporaryDirectory '/tmp/tmpbi9pwo3j'>
+teardown_module       <TemporaryDirectory '/tmp/tmpaq1r7lnj'>
 

python/examples/pytest/test_fixture.py

@@ -3,32 +3,32 @@
 def setup_module():
     global db_server
     db_server = tempfile.TemporaryDirectory()
-    print(f"setup_module: {db_server}")
+    print(f"setup_module:         {db_server}")
 
 def teardown_module():
-    print(f"teardown_module {db_server}")
+    print(f"teardown_module       {db_server}")
 
 
 def setup_function():
     global db
     db = tempfile.TemporaryDirectory()
-    print(f"  setup_function {db}")
+    print(f"  setup_function                                              {db}")
 
 def teardown_function():
-    print(f"  teardown_function {db}")
+    print(f"  teardown_function                                          {db}")
 
 
 def test_one():
-    print(f"    test_one {db_server} {db}")
+    print(f"    test_one          {db_server} {db}")
     assert True
     print("    test_one after")
 
 def test_two():
-    print(f"    test_two {db_server} {db}")
+    print(f"    test_two          {db_server} {db}")
     assert False
     print("    test_two after")
 
 def test_three():
-    print(f"    test_three {db_server} {db}")
+    print(f"    test_three        {db_server} {db}")
     assert True
     print("    test_three after")

python/examples/pytest/test_functions.out

@@ -1,17 +1,16 @@
 $ pytest -qqs test_functions.py
-
 setup db_server
 new db_serverironment
-setup_db <TemporaryDirectory '/tmp/tmpsqk01wqt'>
-    test_one <TemporaryDirectory '/tmp/tmpsqk01wqt'>
+setup_db             <TemporaryDirectory '/tmp/tmpvct7ng6r'>
+    test_one         <TemporaryDirectory '/tmp/tmpvct7ng6r'>
     test_one after
-teardown_db <TemporaryDirectory '/tmp/tmpsqk01wqt'>
+teardown_db          <TemporaryDirectory '/tmp/tmpvct7ng6r'>
 setup db_server
-setup_db <TemporaryDirectory '/tmp/tmp8qyhchd6'>
-    test_two <TemporaryDirectory '/tmp/tmp8qyhchd6'>
+setup_db             <TemporaryDirectory '/tmp/tmptmaql_a_'>
+    test_two         <TemporaryDirectory '/tmp/tmptmaql_a_'>
 setup db_server
-setup_db <TemporaryDirectory '/tmp/tmpu4ei9yc5'>
-    test_three <TemporaryDirectory '/tmp/tmpu4ei9yc5'>
+setup_db             <TemporaryDirectory '/tmp/tmpwb18nwil'>
+    test_three       <TemporaryDirectory '/tmp/tmpwb18nwil'>
     test_three after
-teardown_db <TemporaryDirectory '/tmp/tmpu4ei9yc5'>
+teardown_db          <TemporaryDirectory '/tmp/tmpwb18nwil'>
 

python/examples/pytest/test_functions.py

@@ -3,7 +3,7 @@
 def test_one():
     db_server = setup_db_server()
     db = setup_db()
-    print(f"    test_one {db}")
+    print(f"    test_one         {db}")
     assert True
     print("    test_one after")
     teardown_db(db)
@@ -12,7 +12,7 @@ def test_one():
 def test_two():
     db_server = setup_db_server()
     db = setup_db()
-    print(f"    test_two {db}")
+    print(f"    test_two         {db}")
     assert False
     print("    test_two after")
     teardown_db(db)
@@ -21,7 +21,7 @@ def test_two():
 def test_three():
     db_server = setup_db_server()
     db = setup_db()
-    print(f"    test_three {db}")
+    print(f"    test_three       {db}")
     assert True
     print("    test_three after")
     teardown_db(db)
@@ -30,12 +30,12 @@ def test_three():
 def setup_db():
     db = tempfile.TemporaryDirectory()
     ...
-    print(f"setup_db {db}")
+    print(f"setup_db             {db}")
     return db
 
 def teardown_db(db):
     ...
-    print(f"teardown_db {db}")
+    print(f"teardown_db          {db}")
 
 
 def setup_db_server():

python/pytest-fixtures.md

@@ -120,10 +120,22 @@ def serve_bolognese(pasta, sauce):
 {id: pytest-tmpdir}
 {i: tmpdir}
 
+* Probably the simples fixture that PyTest can provide is the `tmpdir`.
+* Pytest will prepare a temporary directory and call the test function passing the path to the `tmpdir`.
+* PyTest will also clean up the temporary folder, though it will keep the 3 most recent ones. (this is configurable)
+
 ![](examples/pytest/test_tmpdir.py)
 
 ## Pytest and tempdir
 {id: pytest-tempdir}
+{i: tmpdir}
+
+* This is a simple application that reads and writes config files (ini file).
+* We can test the `parse_file` by preparing some input files and check if we get the expected data structure.
+* In order to test the `save_file` we need to be able to save a file somewhere.
+* Saving it in the current folder will create garbage files. (and the folder might be read-only in some environments).
+* For each test we'll have to come up with a separate filename so they won't collide.
+* Using a `tmpdir` solves this problem.
 
 ![](examples/pytest/mycfg.py)
 ![](examples/pytest/a.cfg)