tests/integration/workspace.py: Add incremental build test

Verify basic incremental build and proper mtime handling.

3 files changed, 84 insertions, 0 deletions

diff --git a/tests/integration/project/files/workspace-incremental/Makefile b/tests/integration/project/files/workspace-incremental/Makefile
new file mode 100644
index 000000000..18333fd46
--- /dev/null
+++ b/tests/integration/project/files/workspace-incremental/Makefile
@@ -0,0 +1,7 @@
+all: random copy
+
+random:
+	dd if=/dev/urandom count=8 | sha256sum > random
+
+copy: source
+	cp source copy
diff --git a/tests/integration/project/files/workspace-incremental/source b/tests/integration/project/files/workspace-incremental/source
new file mode 100644
index 000000000..56a6051ca
--- /dev/null
+++ b/tests/integration/project/files/workspace-incremental/source
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/tests/integration/workspace.py b/tests/integration/workspace.py
index d0608f450..b94b87f1c 100644
--- a/tests/integration/workspace.py
+++ b/tests/integration/workspace.py
@@ -8,6 +8,9 @@ from buildstream import _yaml
 from buildstream.testing import cli_integration as cli  # pylint: disable=unused-import
 from buildstream.testing._utils.site import HAVE_SANDBOX
 from buildstream.exceptions import ErrorDomain
+from buildstream.utils import BST_ARBITRARY_TIMESTAMP
+
+from tests.testutils import wait_for_cache_granularity
 
 
 pytestmark = pytest.mark.integration
@@ -376,3 +379,76 @@ def test_workspace_failed_logs(cli, datafiles):
     fail_str = "FAILURE {}: Running build-commands".format(element_name)
     batch_fail_str = "FAILURE {}: Running commands".format(element_name)
     assert fail_str in log or batch_fail_str in log
+
+
+def get_buildtree_file_contents(cli, project, element_name, filename):
+    res = cli.run(
+        project=project, args=["shell", "--build", element_name, "--use-buildtree", "always", "--", "cat", filename,],
+    )
+    res.assert_success()
+    return res.output
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.skipif(not HAVE_SANDBOX, reason="Only available with a functioning sandbox")
+def test_incremental(cli, datafiles):
+    project = str(datafiles)
+    workspace = os.path.join(cli.directory, "workspace")
+    element_path = os.path.join(project, "elements")
+    element_name = "workspace/incremental.bst"
+
+    element = {
+        "kind": "manual",
+        "depends": [{"filename": "base.bst", "type": "build"}],
+        "sources": [{"kind": "local", "path": "files/workspace-incremental"}],
+        "config": {"build-commands": ["make"]},
+    }
+    _yaml.roundtrip_dump(element, os.path.join(element_path, element_name))
+
+    # We open a workspace on the above element
+    res = cli.run(project=project, args=["workspace", "open", "--directory", workspace, element_name])
+    res.assert_success()
+
+    # Initial (non-incremental) build of the workspace
+    res = cli.run(project=project, args=["build", element_name])
+    res.assert_success()
+
+    # Save the random hash
+    random_hash = get_buildtree_file_contents(cli, project, element_name, "random")
+
+    # Verify the expected output file of the initial build
+    assert get_buildtree_file_contents(cli, project, element_name, "copy") == "1"
+
+    wait_for_cache_granularity()
+
+    # Replace source file contents with '2'
+    with open(os.path.join(workspace, "source"), "w") as f:
+        f.write("2")
+
+    # Perform incremental build of the workspace
+    res = cli.run(project=project, args=["build", element_name])
+    res.assert_success()
+
+    # Verify that this was an incremental build by comparing the random hash
+    assert get_buildtree_file_contents(cli, project, element_name, "random") == random_hash
+
+    # Verify that the output file matches the new source file
+    assert get_buildtree_file_contents(cli, project, element_name, "copy") == "2"
+
+    wait_for_cache_granularity()
+
+    # Replace source file contents with '3', however, set an old mtime such
+    # that `make` will not pick up the change
+    with open(os.path.join(workspace, "source"), "w") as f:
+        f.write("3")
+    os.utime(os.path.join(workspace, "source"), (BST_ARBITRARY_TIMESTAMP, BST_ARBITRARY_TIMESTAMP))
+
+    # Perform incremental build of the workspace
+    res = cli.run(project=project, args=["build", element_name])
+    res.assert_success()
+
+    # Verify that this was an incremental build by comparing the random hash
+    assert get_buildtree_file_contents(cli, project, element_name, "random") == random_hash
+
+    # Verify that the output file still matches the previous content '2'
+    assert get_buildtree_file_contents(cli, project, element_name, "copy") == "2"