From bd3c7dba8bb2f6ae0b5305b6f0f406637ce8b345 Mon Sep 17 00:00:00 2001
From: lmtierney <lucast1533@gmail.com>
Date: Thu, 8 Feb 2018 19:38:18 -0600
Subject: [PATCH 1/2] Ensure loadscope and loadfile work when the first scope
 has one work unit

---
 changelog/257.bugfix         |  1 +
 testing/acceptance_test.py   | 64 ++++++++++++++++++++++++++++++++++++
 xdist/scheduler/loadscope.py |  4 +++
 3 files changed, 69 insertions(+)
 create mode 100644 changelog/257.bugfix

diff --git a/changelog/257.bugfix b/changelog/257.bugfix
new file mode 100644
index 0000000..6b3cde6
--- /dev/null
+++ b/changelog/257.bugfix
@@ -0,0 +1 @@
+Fix issue when using ``loadscope`` or ``loadfile`` where tests would fail to start if the first scope had only one test.
diff --git a/testing/acceptance_test.py b/testing/acceptance_test.py
index 56ecc0b..2ecff57 100644
--- a/testing/acceptance_test.py
+++ b/testing/acceptance_test.py
@@ -888,6 +888,38 @@ class TestLoadScope:
         assert get_workers_and_test_count_by_prefix(
             'test_a.py::TestB', result.outlines) in ({'gw0': 10}, {'gw1': 10})
 
+    def test_module_single_start(self, testdir):
+        test_file1 = """
+            import pytest
+            def test():
+                pass
+        """
+        test_file2 = """
+            import pytest
+            def test_1():
+                pass
+            def test_2():
+                pass
+        """
+        testdir.makepyfile(
+            test_a=test_file1,
+            test_b=test_file1,
+            test_c=test_file2
+        )
+        result = testdir.runpytest('-n2', '--dist=loadscope', '-v')
+        a = get_workers_and_test_count_by_prefix('test_a.py::test',
+                                                 result.outlines)
+        b = get_workers_and_test_count_by_prefix('test_b.py::test',
+                                                 result.outlines)
+        c1 = get_workers_and_test_count_by_prefix('test_c.py::test_1',
+                                                  result.outlines)
+        c2 = get_workers_and_test_count_by_prefix('test_c.py::test_2',
+                                                  result.outlines)
+        assert a in ({'gw0': 1}, {'gw1': 1})
+        assert b in ({'gw0': 1}, {'gw1': 1})
+        assert a.items() != b.items()
+        assert c1 == c2
+
 
 class TestFileScope:
 
@@ -943,6 +975,38 @@ class TestFileScope:
         assert test_b_workers_and_test_count in ({'gw0': 10}, {'gw1': 0}) or \
             test_b_workers_and_test_count in ({'gw0': 0}, {'gw1': 10})
 
+    def test_module_single_start(self, testdir):
+        test_file1 = """
+            import pytest
+            def test():
+                pass
+        """
+        test_file2 = """
+            import pytest
+            def test_1():
+                pass
+            def test_2():
+                pass
+        """
+        testdir.makepyfile(
+            test_a=test_file1,
+            test_b=test_file1,
+            test_c=test_file2
+        )
+        result = testdir.runpytest('-n2', '--dist=loadfile', '-v')
+        a = get_workers_and_test_count_by_prefix('test_a.py::test',
+                                                 result.outlines)
+        b = get_workers_and_test_count_by_prefix('test_b.py::test',
+                                                 result.outlines)
+        c1 = get_workers_and_test_count_by_prefix('test_c.py::test_1',
+                                                  result.outlines)
+        c2 = get_workers_and_test_count_by_prefix('test_c.py::test_2',
+                                                  result.outlines)
+        assert a in ({'gw0': 1}, {'gw1': 1})
+        assert b in ({'gw0': 1}, {'gw1': 1})
+        assert a.items() != b.items()
+        assert c1 == c2
+
 
 def parse_tests_and_workers_from_output(lines):
     result = []
diff --git a/xdist/scheduler/loadscope.py b/xdist/scheduler/loadscope.py
index 4c51f7d..0677e3e 100644
--- a/xdist/scheduler/loadscope.py
+++ b/xdist/scheduler/loadscope.py
@@ -380,6 +380,10 @@ class LoadScopeScheduling:
         for node in self.nodes:
             self._assign_work_unit(node)
 
+        # Ensure nodes start with at least two work units if possible
+        for node in self.nodes:
+            self._reschedule(node)
+
         # Initial distribution sent all tests, start node shutdown
         if not self.workqueue:
             for node in self.nodes:

From 1be8a463ffe1ad06987442d210032a1dbc4af968 Mon Sep 17 00:00:00 2001
From: Bruno Oliveira <nicoddemus@gmail.com>
Date: Fri, 16 Feb 2018 20:13:56 -0200
Subject: [PATCH 2/2] Add docstring to tests for #277

---
 testing/acceptance_test.py   | 2 ++
 xdist/scheduler/loadscope.py | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/testing/acceptance_test.py b/testing/acceptance_test.py
index 2ecff57..697070e 100644
--- a/testing/acceptance_test.py
+++ b/testing/acceptance_test.py
@@ -889,6 +889,7 @@ class TestLoadScope:
             'test_a.py::TestB', result.outlines) in ({'gw0': 10}, {'gw1': 10})
 
     def test_module_single_start(self, testdir):
+        """Fix test suite never finishing in case all workers start with a single test (#277)."""
         test_file1 = """
             import pytest
             def test():
@@ -976,6 +977,7 @@ class TestFileScope:
             test_b_workers_and_test_count in ({'gw0': 0}, {'gw1': 10})
 
     def test_module_single_start(self, testdir):
+        """Fix test suite never finishing in case all workers start with a single test (#277)."""
         test_file1 = """
             import pytest
             def test():
diff --git a/xdist/scheduler/loadscope.py b/xdist/scheduler/loadscope.py
index 0677e3e..3c8381a 100644
--- a/xdist/scheduler/loadscope.py
+++ b/xdist/scheduler/loadscope.py
@@ -380,7 +380,7 @@ class LoadScopeScheduling:
         for node in self.nodes:
             self._assign_work_unit(node)
 
-        # Ensure nodes start with at least two work units if possible
+        # Ensure nodes start with at least two work units if possible (#277)
         for node in self.nodes:
             self._reschedule(node)