From 36159776088c8d9697e09c0c696ed78810a0226e Mon Sep 17 00:00:00 2001
From: Wil Cooley <wcooley@nakedape.cc>
Date: Thu, 14 Jun 2018 12:20:06 -0700
Subject: [PATCH] Add `messages` property to `caplog` fixture.

---
 AUTHORS                         |  1 +
 changelog/3579.feature.rst      |  1 +
 src/_pytest/logging.py          | 16 ++++++++++++++++
 testing/logging/test_fixture.py | 21 +++++++++++++++++++++
 4 files changed, 39 insertions(+)
 create mode 100644 changelog/3579.feature.rst

diff --git a/AUTHORS b/AUTHORS
index 3edfdcf85..81f79d609 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -204,6 +204,7 @@ Victor Uriarte
 Vidar T. Fauske
 Vitaly Lashmanov
 Vlad Dragos
+Wil Cooley
 William Lee
 Wouter van Ackooy
 Xuan Luong
diff --git a/changelog/3579.feature.rst b/changelog/3579.feature.rst
new file mode 100644
index 000000000..575af006f
--- /dev/null
+++ b/changelog/3579.feature.rst
@@ -0,0 +1 @@
+Fixture ``caplog`` now has a ``messages`` property, providing convenient access to the format-interpolated log messages without the extra data provided by the formatter/handler.
diff --git a/src/_pytest/logging.py b/src/_pytest/logging.py
index 00bb9aeb5..615e87262 100644
--- a/src/_pytest/logging.py
+++ b/src/_pytest/logging.py
@@ -270,6 +270,22 @@ class LogCaptureFixture(object):
         """
         return [(r.name, r.levelno, r.getMessage()) for r in self.records]
 
+    @property
+    def messages(self):
+        """Returns a list of format-interpolated log messages.
+
+        Unlike 'records', which contains the format string and parameters for interpolation, log messages in this list
+        are all interpolated.
+        Unlike 'text', which contains the output from the handler, log messages in this list are unadorned with
+        levels, timestamps, etc, making exact comparisions more reliable.
+
+        Note that traceback or stack info (from :func:`logging.exception` or the `exc_info` or `stack_info` arguments
+        to the logging functions) is not included, as this is added by the formatter in the handler.
+
+        .. versionadded:: 3.7
+        """
+        return [r.getMessage() for r in self.records]
+
     def clear(self):
         """Reset the list of log records and the captured log text."""
         self.handler.reset()
diff --git a/testing/logging/test_fixture.py b/testing/logging/test_fixture.py
index 8d9ae6b51..f19813926 100644
--- a/testing/logging/test_fixture.py
+++ b/testing/logging/test_fixture.py
@@ -73,6 +73,27 @@ def test_log_access(caplog):
     assert "boo arg" in caplog.text
 
 
+def test_messages(caplog):
+    caplog.set_level(logging.INFO)
+    logger.info("boo %s", "arg")
+    logger.info("bar %s\nbaz %s", "arg1", "arg2")
+    assert "boo arg" == caplog.messages[0]
+    assert "bar arg1\nbaz arg2" == caplog.messages[1]
+    assert caplog.text.count("\n") > len(caplog.messages)
+    assert len(caplog.text.splitlines()) > len(caplog.messages)
+
+    try:
+        raise Exception("test")
+    except Exception:
+        logger.exception("oops")
+
+    assert "oops" in caplog.text
+    assert "oops" in caplog.messages[-1]
+    # Tracebacks are stored in the record and not added until the formatter or handler.
+    assert "Exception" in caplog.text
+    assert "Exception" not in caplog.messages[-1]
+
+
 def test_record_tuples(caplog):
     caplog.set_level(logging.INFO)
     logger.info("boo %s", "arg")