doc: document inversed lines with terminal report hooks (#7016)

It was surprising that `tryfirst=True` would not result in lines being
added to the beginning with `pytest_report_header`.
This is due to lines being reversed, and therefore the same applies to
`pytest_report_collectionfinish`.

1 files changed, 15 insertions, 1 deletions

diff --git a/src/_pytest/hookspec.py b/src/_pytest/hookspec.py
index 962ec8b3a..210cf2255 100644
--- a/src/_pytest/hookspec.py
+++ b/src/_pytest/hookspec.py
@@ -530,6 +530,13 @@ def pytest_report_header(config, startdir):
 
     .. note::
 
+        Lines returned by a plugin are displayed before those of plugins which
+        ran before it.
+        If you want to have your line(s) displayed first, use
+        :ref:`trylast=True <plugin-hookorder>`.
+
+    .. note::
+
         This function should be implemented only in plugins or ``conftest.py``
         files situated at the tests root directory due to how pytest
         :ref:`discovers plugins during startup <pluginorder>`.
@@ -542,11 +549,18 @@ def pytest_report_collectionfinish(config, startdir, items):
 
     return a string or list of strings to be displayed after collection has finished successfully.
 
-    This strings will be displayed after the standard "collected X items" message.
+    These strings will be displayed after the standard "collected X items" message.
 
     :param _pytest.config.Config config: pytest config object
     :param startdir: py.path object with the starting dir
     :param items: list of pytest items that are going to be executed; this list should not be modified.
+
+    .. note::
+
+        Lines returned by a plugin are displayed before those of plugins which
+        ran before it.
+        If you want to have your line(s) displayed first, use
+        :ref:`trylast=True <plugin-hookorder>`.
     """