From 17c544e793f95a7e0423114a435ff51c17e8ad5e Mon Sep 17 00:00:00 2001
From: Bruno Oliveira <nicoddemus@gmail.com>
Date: Thu, 27 Jul 2017 10:34:49 -0300
Subject: [PATCH] Introduce new pytest_report_collectionfinish hook

Fix #2622
---
 _pytest/hookspec.py        | 16 +++++++++++++++-
 _pytest/terminal.py        | 10 ++++++----
 changelog/2622.feature     |  2 ++
 doc/en/writing_plugins.rst |  1 +
 testing/test_terminal.py   | 17 +++++++++++++++++
 5 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 changelog/2622.feature

diff --git a/_pytest/hookspec.py b/_pytest/hookspec.py
index 43667d701c2..f7b53e892d8 100644
--- a/_pytest/hookspec.py
+++ b/_pytest/hookspec.py
@@ -337,7 +337,10 @@ def pytest_assertrepr_compare(config, op, left, right):
 
 
 def pytest_report_header(config, startdir):
-    """ return a string to be displayed as header info for terminal reporting.
+    """ return a string or list of strings to be displayed as header info for terminal reporting.
+
+    :param config: the pytest config object.
+    :param startdir: py.path object with the starting dir
 
     .. note::
 
@@ -347,6 +350,17 @@ def pytest_report_header(config, startdir):
     """
 
 
+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.
+
+    :param config: the 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.
+    """
+
+
 @hookspec(firstresult=True)
 def pytest_report_teststatus(report):
     """ return result-category, shortletter and verbose word for reporting.
diff --git a/_pytest/terminal.py b/_pytest/terminal.py
index 10f37c6a137..7dd10924ae6 100644
--- a/_pytest/terminal.py
+++ b/_pytest/terminal.py
@@ -323,6 +323,9 @@ def pytest_sessionstart(self, session):
         self.write_line(msg)
         lines = self.config.hook.pytest_report_header(
             config=self.config, startdir=self.startdir)
+        self._write_report_lines_from_hooks(lines)
+
+    def _write_report_lines_from_hooks(self, lines):
         lines.reverse()
         for line in flatten(lines):
             self.write_line(line)
@@ -349,10 +352,9 @@ def pytest_collection_finish(self, session):
                     rep.toterminal(self._tw)
                 return 1
             return 0
-        if not self.showheader:
-            return
-        # for i, testarg in enumerate(self.config.args):
-        #    self.write_line("test path %d: %s" %(i+1, testarg))
+        lines = self.config.hook.pytest_report_collectionfinish(
+            config=self.config, startdir=self.startdir, items=session.items)
+        self._write_report_lines_from_hooks(lines)
 
     def _printcollecteditems(self, items):
         # to print out items and their parent collectors
diff --git a/changelog/2622.feature b/changelog/2622.feature
new file mode 100644
index 00000000000..2988922004c
--- /dev/null
+++ b/changelog/2622.feature
@@ -0,0 +1,2 @@
+New ``pytest_report_collectionfinish`` hook which allows plugins to add messages to the terminal reporting after
+collection has been finished successfully.
diff --git a/doc/en/writing_plugins.rst b/doc/en/writing_plugins.rst
index 26e1a8a695b..3eb7d784ef5 100644
--- a/doc/en/writing_plugins.rst
+++ b/doc/en/writing_plugins.rst
@@ -644,6 +644,7 @@ Session related reporting hooks:
 .. autofunction:: pytest_collectreport
 .. autofunction:: pytest_deselected
 .. autofunction:: pytest_report_header
+.. autofunction:: pytest_report_collectionfinish
 .. autofunction:: pytest_report_teststatus
 .. autofunction:: pytest_terminal_summary
 .. autofunction:: pytest_fixture_setup
diff --git a/testing/test_terminal.py b/testing/test_terminal.py
index bac3ab8b128..6b20c3a487b 100644
--- a/testing/test_terminal.py
+++ b/testing/test_terminal.py
@@ -544,6 +544,23 @@ def test_more_quiet_reporting(self, testdir):
         assert "===" not in s
         assert "passed" not in s
 
+    def test_report_collectionfinish_hook(self, testdir):
+        testdir.makeconftest("""
+            def pytest_report_collectionfinish(config, startdir, items):
+                return ['hello from hook: {0} items'.format(len(items))]
+        """)
+        testdir.makepyfile("""
+            import pytest
+            @pytest.mark.parametrize('i', range(3))
+            def test(i):
+                pass
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines([
+            "collected 3 items",
+            "hello from hook: 3 items",
+        ])
+
 
 def test_fail_extra_reporting(testdir):
     testdir.makepyfile("def test_this(): assert 0")