Add support for include '(@)' in project.conf and .bst files

Fixes #331.

47 files changed, 583 insertions, 0 deletions

diff --git a/tests/format/include.py b/tests/format/include.py
new file mode 100644
index 000000000..36e723ed0
--- /dev/null
+++ b/tests/format/include.py
@@ -0,0 +1,263 @@
+import os
+import pytest
+from buildstream import _yaml
+from buildstream._exceptions import ErrorDomain, LoadErrorReason
+from tests.testutils import cli, generate_junction, create_repo
+
+
+# Project directory
+DATA_DIR = os.path.join(
+    os.path.dirname(os.path.realpath(__file__)),
+    'include'
+)
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_project_file(cli, datafiles):
+    project = os.path.join(str(datafiles), 'file')
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['included'] == 'True'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_junction_file(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'junction')
+
+    generate_junction(tmpdir,
+                      os.path.join(project, 'subproject'),
+                      os.path.join(project, 'junction.bst'),
+                      store_ref=True)
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['included'] == 'True'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_junction_options(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'options')
+
+    result = cli.run(project=project, args=[
+        '-o', 'build_arch', 'x86_64',
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['build_arch'] == 'x86_64'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_junction_element_partial_project_project(cli, tmpdir, datafiles):
+    """
+    Junction elements never depend on fully include processed project.
+    """
+
+    project = os.path.join(str(datafiles), 'junction')
+
+    subproject_path = os.path.join(project, 'subproject')
+    junction_path = os.path.join(project, 'junction.bst')
+
+    repo = create_repo('git', str(tmpdir))
+
+    ref = repo.create(subproject_path)
+
+    element = {
+        'kind': 'junction',
+        'sources': [
+            repo.source_config(ref=ref)
+        ]
+    }
+    _yaml.dump(element, junction_path)
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'junction.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'included' not in loaded
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_junction_element_not_partial_project_file(cli, tmpdir, datafiles):
+    """
+    Junction elements never depend on fully include processed project.
+    """
+
+    project = os.path.join(str(datafiles), 'file_with_subproject')
+
+    subproject_path = os.path.join(project, 'subproject')
+    junction_path = os.path.join(project, 'junction.bst')
+
+    repo = create_repo('git', str(tmpdir))
+
+    ref = repo.create(subproject_path)
+
+    element = {
+        'kind': 'junction',
+        'sources': [
+            repo.source_config(ref=ref)
+        ]
+    }
+    _yaml.dump(element, junction_path)
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'junction.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'included' in loaded
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_element_overrides(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'overrides')
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'manual_main_override' in loaded
+    assert 'manual_included_override' in loaded
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_element_overrides_composition(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'overrides')
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{config}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'build-commands' in loaded
+    assert loaded['build-commands'] == ['first', 'second']
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_element_overrides_sub_include(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'sub-include')
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'included' in loaded
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_junction_do_not_use_included_overrides(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'overrides-junction')
+
+    generate_junction(tmpdir,
+                      os.path.join(project, 'subproject'),
+                      os.path.join(project, 'junction.bst'),
+                      store_ref=True)
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'junction.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'main_override' in loaded
+    assert 'included_override' not in loaded
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_conditional_in_fragment(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'conditional')
+
+    result = cli.run(project=project, args=[
+        '-o', 'build_arch', 'x86_64',
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert 'size' in loaded
+    assert loaded['size'] == '8'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_inner(cli, datafiles):
+    project = os.path.join(str(datafiles), 'inner')
+    result = cli.run(project=project, args=[
+        '-o', 'build_arch', 'x86_64',
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['build_arch'] == 'x86_64'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_recusive_include(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'recursive')
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.RECURSIVE_INCLUDE)
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_local_to_junction(cli, tmpdir, datafiles):
+    project = os.path.join(str(datafiles), 'local_to_junction')
+
+    generate_junction(tmpdir,
+                      os.path.join(project, 'subproject'),
+                      os.path.join(project, 'junction.bst'),
+                      store_ref=True)
+
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['included'] == 'True'
+
+
+@pytest.mark.datafiles(DATA_DIR)
+def test_include_project_file(cli, datafiles):
+    project = os.path.join(str(datafiles), 'string')
+    result = cli.run(project=project, args=[
+        'show',
+        '--deps', 'none',
+        '--format', '%{vars}',
+        'element.bst'])
+    result.assert_success()
+    loaded = _yaml.load_data(result.output)
+    assert loaded['included'] == 'True'
diff --git a/tests/format/include/conditional/element.bst b/tests/format/include/conditional/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/conditional/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/conditional/extra_conf.yml b/tests/format/include/conditional/extra_conf.yml
new file mode 100644
index 000000000..dd58c9855
--- /dev/null
+++ b/tests/format/include/conditional/extra_conf.yml
@@ -0,0 +1,6 @@
+variables:
+  (?):
+    - build_arch == "i586":
+        size: "4"
+    - build_arch == "x86_64":
+        size: "8"
diff --git a/tests/format/include/conditional/project.conf b/tests/format/include/conditional/project.conf
new file mode 100644
index 000000000..cb54779d3
--- /dev/null
+++ b/tests/format/include/conditional/project.conf
@@ -0,0 +1,13 @@
+name: test
+
+options:
+  build_arch:
+    type: arch
+    description: Architecture
+    variable: build_arch
+    values:
+      - i586
+      - x86_64
+
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/file/element.bst b/tests/format/include/file/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/file/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/file/extra_conf.yml b/tests/format/include/file/extra_conf.yml
new file mode 100644
index 000000000..404ecd6dd
--- /dev/null
+++ b/tests/format/include/file/extra_conf.yml
@@ -0,0 +1,2 @@
+variables:
+  included: 'True'
diff --git a/tests/format/include/file/project.conf b/tests/format/include/file/project.conf
new file mode 100644
index 000000000..a7791a416
--- /dev/null
+++ b/tests/format/include/file/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/file_with_subproject/element.bst b/tests/format/include/file_with_subproject/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/file_with_subproject/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/file_with_subproject/extra_conf.yml b/tests/format/include/file_with_subproject/extra_conf.yml
new file mode 100644
index 000000000..404ecd6dd
--- /dev/null
+++ b/tests/format/include/file_with_subproject/extra_conf.yml
@@ -0,0 +1,2 @@
+variables:
+  included: 'True'
diff --git a/tests/format/include/file_with_subproject/project.bst b/tests/format/include/file_with_subproject/project.bst
new file mode 100644
index 000000000..4836c5f8b
--- /dev/null
+++ b/tests/format/include/file_with_subproject/project.bst
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - junction.bst:extra_conf.yml
diff --git a/tests/format/include/file_with_subproject/project.conf b/tests/format/include/file_with_subproject/project.conf
new file mode 100644
index 000000000..a7791a416
--- /dev/null
+++ b/tests/format/include/file_with_subproject/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/file_with_subproject/subproject/project.conf b/tests/format/include/file_with_subproject/subproject/project.conf
new file mode 100644
index 000000000..7a6655421
--- /dev/null
+++ b/tests/format/include/file_with_subproject/subproject/project.conf
@@ -0,0 +1 @@
+name: test-sub
diff --git a/tests/format/include/inner/element.bst b/tests/format/include/inner/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/inner/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/inner/extra_conf.yml b/tests/format/include/inner/extra_conf.yml
new file mode 100644
index 000000000..4c1847b5f
--- /dev/null
+++ b/tests/format/include/inner/extra_conf.yml
@@ -0,0 +1,7 @@
+build_arch:
+  type: arch
+  description: Architecture
+  variable: build_arch
+  values:
+    - i586
+    - x86_64
diff --git a/tests/format/include/inner/project.conf b/tests/format/include/inner/project.conf
new file mode 100644
index 000000000..8bdfc428a
--- /dev/null
+++ b/tests/format/include/inner/project.conf
@@ -0,0 +1,5 @@
+name: test
+
+options:
+  (@):
+    - extra_conf.yml
diff --git a/tests/format/include/junction/element.bst b/tests/format/include/junction/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/junction/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/junction/project.conf b/tests/format/include/junction/project.conf
new file mode 100644
index 000000000..4836c5f8b
--- /dev/null
+++ b/tests/format/include/junction/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - junction.bst:extra_conf.yml
diff --git a/tests/format/include/junction/subproject/extra_conf.yml b/tests/format/include/junction/subproject/extra_conf.yml
new file mode 100644
index 000000000..404ecd6dd
--- /dev/null
+++ b/tests/format/include/junction/subproject/extra_conf.yml
@@ -0,0 +1,2 @@
+variables:
+  included: 'True'
diff --git a/tests/format/include/junction/subproject/project.conf b/tests/format/include/junction/subproject/project.conf
new file mode 100644
index 000000000..7a6655421
--- /dev/null
+++ b/tests/format/include/junction/subproject/project.conf
@@ -0,0 +1 @@
+name: test-sub
diff --git a/tests/format/include/local_to_junction/element.bst b/tests/format/include/local_to_junction/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/local_to_junction/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/local_to_junction/project.conf b/tests/format/include/local_to_junction/project.conf
new file mode 100644
index 000000000..4836c5f8b
--- /dev/null
+++ b/tests/format/include/local_to_junction/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - junction.bst:extra_conf.yml
diff --git a/tests/format/include/local_to_junction/subproject/extra_conf.yml b/tests/format/include/local_to_junction/subproject/extra_conf.yml
new file mode 100644
index 000000000..1c0b8ccdd
--- /dev/null
+++ b/tests/format/include/local_to_junction/subproject/extra_conf.yml
@@ -0,0 +1,2 @@
+(@):
+  - internal.yml
diff --git a/tests/format/include/local_to_junction/subproject/internal.yml b/tests/format/include/local_to_junction/subproject/internal.yml
new file mode 100644
index 000000000..404ecd6dd
--- /dev/null
+++ b/tests/format/include/local_to_junction/subproject/internal.yml
@@ -0,0 +1,2 @@
+variables:
+  included: 'True'
diff --git a/tests/format/include/local_to_junction/subproject/project.conf b/tests/format/include/local_to_junction/subproject/project.conf
new file mode 100644
index 000000000..7a6655421
--- /dev/null
+++ b/tests/format/include/local_to_junction/subproject/project.conf
@@ -0,0 +1 @@
+name: test-sub
diff --git a/tests/format/include/options/element.bst b/tests/format/include/options/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/options/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/options/extra_conf.yml b/tests/format/include/options/extra_conf.yml
new file mode 100644
index 000000000..ad1401e0a
--- /dev/null
+++ b/tests/format/include/options/extra_conf.yml
@@ -0,0 +1,8 @@
+options:
+  build_arch:
+    type: arch
+    description: Architecture
+    variable: build_arch
+    values:
+      - i586
+      - x86_64
diff --git a/tests/format/include/options/project.conf b/tests/format/include/options/project.conf
new file mode 100644
index 000000000..a7791a416
--- /dev/null
+++ b/tests/format/include/options/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/overrides-junction/element.bst b/tests/format/include/overrides-junction/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/overrides-junction/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/overrides-junction/project.conf b/tests/format/include/overrides-junction/project.conf
new file mode 100644
index 000000000..d03bec634
--- /dev/null
+++ b/tests/format/include/overrides-junction/project.conf
@@ -0,0 +1,20 @@
+name: test
+
+elements:
+  junction:
+    variables:
+      main_override: True
+  manual:
+    variables:
+      manual_main_override: True
+    config:
+      build-commands:
+        - "first"
+
+sources:
+  git:
+    variables:
+      from_main: True
+
+(@):
+  - junction.bst:extra_conf.yml
diff --git a/tests/format/include/overrides-junction/subproject/extra_conf.yml b/tests/format/include/overrides-junction/subproject/extra_conf.yml
new file mode 100644
index 000000000..3cd3530c5
--- /dev/null
+++ b/tests/format/include/overrides-junction/subproject/extra_conf.yml
@@ -0,0 +1,16 @@
+elements:
+  junction:
+    variables:
+      included_override: True
+  manual:
+    variables:
+      manual_included_override: True
+    config:
+      build-commands:
+        (>):
+          - "second"
+
+sources:
+  git:
+    variables:
+      from_included: True
diff --git a/tests/format/include/overrides-junction/subproject/project.conf b/tests/format/include/overrides-junction/subproject/project.conf
new file mode 100644
index 000000000..7a6655421
--- /dev/null
+++ b/tests/format/include/overrides-junction/subproject/project.conf
@@ -0,0 +1 @@
+name: test-sub
diff --git a/tests/format/include/overrides/element.bst b/tests/format/include/overrides/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/overrides/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/overrides/extra_conf.yml b/tests/format/include/overrides/extra_conf.yml
new file mode 100644
index 000000000..ccb874bd7
--- /dev/null
+++ b/tests/format/include/overrides/extra_conf.yml
@@ -0,0 +1,15 @@
+elements:
+  junction:
+    variables:
+      included_override: True
+  manual:
+    variables:
+      manual_included_override: True
+    config:
+      build-commands:
+        - "ignored"
+
+sources:
+  git:
+    variables:
+      from_included: True
diff --git a/tests/format/include/overrides/extra_conf2.yml b/tests/format/include/overrides/extra_conf2.yml
new file mode 100644
index 000000000..750abd725
--- /dev/null
+++ b/tests/format/include/overrides/extra_conf2.yml
@@ -0,0 +1,5 @@
+elements:
+  manual:
+    config:
+      build-commands:
+        - "first"
diff --git a/tests/format/include/overrides/project.conf b/tests/format/include/overrides/project.conf
new file mode 100644
index 000000000..fa3c75703
--- /dev/null
+++ b/tests/format/include/overrides/project.conf
@@ -0,0 +1,22 @@
+name: test
+
+elements:
+  junction:
+    variables:
+      main_override: True
+  manual:
+    variables:
+      manual_main_override: True
+    config:
+      build-commands:
+        (>):
+          - "second"
+
+sources:
+  git:
+    variables:
+      from_main: True
+
+(@):
+  - extra_conf.yml
+  - extra_conf2.yml
diff --git a/tests/format/include/overrides/subproject/project.conf b/tests/format/include/overrides/subproject/project.conf
new file mode 100644
index 000000000..7a6655421
--- /dev/null
+++ b/tests/format/include/overrides/subproject/project.conf
@@ -0,0 +1 @@
+name: test-sub
diff --git a/tests/format/include/recursive/element.bst b/tests/format/include/recursive/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/recursive/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/recursive/extra_conf.yml b/tests/format/include/recursive/extra_conf.yml
new file mode 100644
index 000000000..57db0d3c6
--- /dev/null
+++ b/tests/format/include/recursive/extra_conf.yml
@@ -0,0 +1,2 @@
+(@):
+  - extra_conf2.yml
diff --git a/tests/format/include/recursive/extra_conf2.yml b/tests/format/include/recursive/extra_conf2.yml
new file mode 100644
index 000000000..e8dd5e2ed
--- /dev/null
+++ b/tests/format/include/recursive/extra_conf2.yml
@@ -0,0 +1,2 @@
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/recursive/project.conf b/tests/format/include/recursive/project.conf
new file mode 100644
index 000000000..a7791a416
--- /dev/null
+++ b/tests/format/include/recursive/project.conf
@@ -0,0 +1,4 @@
+name: test
+
+(@):
+  - extra_conf.yml
diff --git a/tests/format/include/string/element.bst b/tests/format/include/string/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/string/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/string/extra_conf.yml b/tests/format/include/string/extra_conf.yml
new file mode 100644
index 000000000..404ecd6dd
--- /dev/null
+++ b/tests/format/include/string/extra_conf.yml
@@ -0,0 +1,2 @@
+variables:
+  included: 'True'
diff --git a/tests/format/include/string/project.conf b/tests/format/include/string/project.conf
new file mode 100644
index 000000000..6ee9988e9
--- /dev/null
+++ b/tests/format/include/string/project.conf
@@ -0,0 +1,3 @@
+name: test
+
+(@): extra_conf.yml
diff --git a/tests/format/include/sub-include/element.bst b/tests/format/include/sub-include/element.bst
new file mode 100644
index 000000000..4d7f70266
--- /dev/null
+++ b/tests/format/include/sub-include/element.bst
@@ -0,0 +1 @@
+kind: manual
diff --git a/tests/format/include/sub-include/manual_conf.yml b/tests/format/include/sub-include/manual_conf.yml
new file mode 100644
index 000000000..9c2c0dd34
--- /dev/null
+++ b/tests/format/include/sub-include/manual_conf.yml
@@ -0,0 +1,2 @@
+variables:
+  included: True
diff --git a/tests/format/include/sub-include/project.conf b/tests/format/include/sub-include/project.conf
new file mode 100644
index 000000000..7f7df84c8
--- /dev/null
+++ b/tests/format/include/sub-include/project.conf
@@ -0,0 +1,6 @@
+name: test
+
+elements:
+  manual:
+    (@):
+      - manual_conf.yml
diff --git a/tests/format/include_composition.py b/tests/format/include_composition.py
new file mode 100644
index 000000000..b73fca392
--- /dev/null
+++ b/tests/format/include_composition.py
@@ -0,0 +1,131 @@
+import os
+from buildstream._context import Context
+from buildstream._project import Project
+from buildstream._includes import Includes
+from buildstream import _yaml
+
+
+def make_includes(basedir):
+    _yaml.dump({'name': 'test'},
+               os.path.join(basedir, 'project.conf'))
+    context = Context()
+    project = Project(basedir, context)
+    loader = project.loader
+    return Includes(loader)
+
+
+def test_main_has_prority(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml'],
+                'test': ['main']},
+               str(tmpdir.join('main.yml')))
+
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': ['a']},
+               str(tmpdir.join('a.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['main']
+
+
+def test_include_cannot_append(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml'],
+                'test': ['main']},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': {'(>)': ['a']}},
+               str(tmpdir.join('a.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['main']
+
+
+def test_main_can_append(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml'],
+                'test': {'(>)': ['main']}},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': ['a']},
+               str(tmpdir.join('a.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['a', 'main']
+
+
+def test_sibling_cannot_append_backward(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml', 'b.yml']},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': {'(>)': ['a']}},
+               str(tmpdir.join('a.yml')))
+    _yaml.dump({'test': ['b']},
+               str(tmpdir.join('b.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['b']
+
+
+def test_sibling_can_append_forward(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml', 'b.yml']},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': ['a']},
+               str(tmpdir.join('a.yml')))
+    _yaml.dump({'test': {'(>)': ['b']}},
+               str(tmpdir.join('b.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['a', 'b']
+
+
+def test_lastest_sibling_has_priority(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml', 'b.yml']},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': ['a']},
+               str(tmpdir.join('a.yml')))
+    _yaml.dump({'test': ['b']},
+               str(tmpdir.join('b.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['b']
+
+
+def test_main_keeps_keys(tmpdir):
+    includes = make_includes(str(tmpdir))
+
+    _yaml.dump({'(@)': ['a.yml'],
+                'something': 'else'},
+               str(tmpdir.join('main.yml')))
+    main = _yaml.load(str(tmpdir.join('main.yml')))
+
+    _yaml.dump({'test': ['a']},
+               str(tmpdir.join('a.yml')))
+
+    includes.process(main)
+
+    assert main['test'] == ['a']
+    assert main['something'] == 'else'