plugins/elements/stack.py: Require all dependencies be build & run.

Stack elements cannot be build-only dependencies, as this would defeat
the purpose of using stack elements in order to directly build-depend on
them.

Stack element dependencies must all be built in order to build depend
on them, and as such we gain no build parallelism by allowing runtime-only
dependencies on stack elements. Declaring a runtime-only dependency on
a stack element as a whole might still be useful, but still requires the
entire stack to be built at the time we need that stack.

Instead, it is more useful to ensure that a stack element is a logical
group of all dependencies, including runtime dependencies, such that we
can guarantee cache key alignment with all stack dependencies.

This allows for stronger reliability in commands such as
`bst artifact checkout`, which can now reliably download and checkout
a fully built stack as a result, without any uncertainty about possible
runtime-only dependencies which might exist in the project where that
artifact was created.

This consequently closes #1075

This also fixes the following tests such that the no longer
require build-depends or runtime-depends to work in stack elements:

 * tests/frontend/default_target.py: Was not necessary to check results of show,
   these stacks were set to runtime-depends so that they would have the same
   buildable state as their dependencies when shown.

 * tests/format/dependencies.py: tests/frontend/pull.py, test/frontend/show.py,
   tests/integration/compose.py:
   These tests were using specific build/runtime dependencies in stacks, but
   for no particular reason.

9 files changed, 34 insertions, 30 deletions

diff --git a/tests/format/dependencies1/elements/builddep-list.bst b/tests/format/dependencies1/elements/builddep-list.bst
index a0cbcaf23..eb216a127 100644
--- a/tests/format/dependencies1/elements/builddep-list.bst
+++ b/tests/format/dependencies1/elements/builddep-list.bst
@@ -1,4 +1,4 @@
-kind: stack
+kind: manual
 description: This element has a build-only dependency specified via build-depends
 build-depends:
-  - firstdep.bst
+- firstdep.bst
diff --git a/tests/format/dependencies1/elements/list-combine.bst b/tests/format/dependencies1/elements/list-combine.bst
index ed3452206..d39ddd38b 100644
--- a/tests/format/dependencies1/elements/list-combine.bst
+++ b/tests/format/dependencies1/elements/list-combine.bst
@@ -1,4 +1,4 @@
-kind: stack
+kind: manual
 description: This element depends on three elements in different ways
 build-depends:
 - firstdep.bst
diff --git a/tests/format/dependencies1/elements/runtimedep-list.bst b/tests/format/dependencies1/elements/runtimedep-list.bst
index 1207a492d..eaa0cd2e0 100644
--- a/tests/format/dependencies1/elements/runtimedep-list.bst
+++ b/tests/format/dependencies1/elements/runtimedep-list.bst
@@ -1,4 +1,4 @@
-kind: stack
+kind: manual
 description: This element has a runtime-only dependency
 runtime-depends:
-  - firstdep.bst
+- firstdep.bst
diff --git a/tests/frontend/default-target/elements/dummy_stack.bst b/tests/frontend/default-target/elements/dummy_stack.bst
index 5f921667f..3ea51b00f 100644
--- a/tests/frontend/default-target/elements/dummy_stack.bst
+++ b/tests/frontend/default-target/elements/dummy_stack.bst
@@ -1,5 +1,5 @@
 kind: stack
 
-runtime-depends:
+depends:
 - dummy_1.bst
 - dummy_2.bst
diff --git a/tests/frontend/default_target.py b/tests/frontend/default_target.py
index bb7a49592..60578bb8e 100644
--- a/tests/frontend/default_target.py
+++ b/tests/frontend/default_target.py
@@ -13,27 +13,27 @@ from tests.testutils import create_artifact_share
 DATA_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "default-target",)
 
 
-###################################
-#      build/show operations      #
-###################################
-
-
+#
+# When no target is default, then expect all targets to be built
+#
 @pytest.mark.datafiles(DATA_DIR)
-@pytest.mark.parametrize("operation,expected_state", [("show", "buildable"), ("build", "cached")])
-def test_no_default(cli, datafiles, operation, expected_state):
+def test_no_default(cli, datafiles):
     project = str(datafiles)
     all_targets = ["dummy_1.bst", "dummy_2.bst", "dummy_3.bst", "dummy_stack.bst"]
 
-    result = cli.run(project=project, args=[operation])
+    result = cli.run(project=project, args=["build"])
     result.assert_success()
 
     states = cli.get_element_states(project, all_targets)
-    assert all(states[e] == expected_state for e in all_targets)
+    assert all(states[e] == "cached" for e in all_targets)
 
 
+#
+# When the stack is specified as the default target, then
+# expect only it and it's dependencies to be built
+#
 @pytest.mark.datafiles(DATA_DIR)
-@pytest.mark.parametrize("operation,expected_state", [("show", "buildable"), ("build", "cached")])
-def test_default_target(cli, datafiles, operation, expected_state):
+def test_default_target(cli, datafiles):
     project = str(datafiles)
     project_path = os.path.join(project, "project.conf")
 
@@ -49,19 +49,23 @@ def test_default_target(cli, datafiles, operation, expected_state):
     # dummy_stack only depends on dummy_1 and dummy_2, but not dummy_3
     all_targets = ["dummy_1.bst", "dummy_2.bst", "dummy_stack.bst"]
 
-    result = cli.run(project=project, args=[operation])
+    result = cli.run(project=project, args=["build"])
     result.assert_success()
 
     states = cli.get_element_states(project, all_targets)
-    assert all(states[e] == expected_state for e in all_targets)
+    assert all(states[e] == "cached" for e in all_targets)
 
     # assert that dummy_3 isn't included in the output
     assert "dummy_3.bst" not in states
 
 
+#
+# Even when there is a junction, expect that the elements in the
+# subproject referred to by the toplevel project are built when
+# calling `bst build` and no default is specified.
+#
 @pytest.mark.datafiles(DATA_DIR)
-@pytest.mark.parametrize("operation,expected_state", [("show", "buildable"), ("build", "cached")])
-def test_no_default_with_junction(cli, datafiles, operation, expected_state):
+def test_no_default_with_junction(cli, datafiles):
     project = str(datafiles)
     junction_path = os.path.join(project, "elements", "junction.bst")
     target_path = os.path.join(project, "elements", "junction-target.bst")
@@ -71,16 +75,16 @@ def test_no_default_with_junction(cli, datafiles, operation, expected_state):
     _yaml.roundtrip_dump(junction_config, junction_path)
 
     # Then, create a stack element with dependency on cross junction element
-    target_config = {"kind": "stack", "runtime-depends": ["junction.bst:dummy_subproject.bst"]}
+    target_config = {"kind": "stack", "depends": ["junction.bst:dummy_subproject.bst"]}
     _yaml.roundtrip_dump(target_config, target_path)
 
-    # Now try to perform the specified operation.
+    # Now try to perform a build
     # This should automatically fetch the junction at load time.
-    result = cli.run(project=project, args=[operation])
+    result = cli.run(project=project, args=["build"])
     result.assert_success()
 
-    assert cli.get_element_state(project, "junction.bst:dummy_subproject.bst") == expected_state
-    assert cli.get_element_state(project, "junction-target.bst") == expected_state
+    assert cli.get_element_state(project, "junction.bst:dummy_subproject.bst") == "cached"
+    assert cli.get_element_state(project, "junction-target.bst") == "cached"
 
 
 ###################################
diff --git a/tests/frontend/pull.py b/tests/frontend/pull.py
index c1fa76ab0..f873ad96e 100644
--- a/tests/frontend/pull.py
+++ b/tests/frontend/pull.py
@@ -338,7 +338,7 @@ def test_pull_missing_local_blob(cli, tmpdir, datafiles):
     _yaml.roundtrip_dump(input_config, input_file)
 
     depends_name = "depends.bst"
-    depends_config = {"kind": "stack", "depends": [{"filename": input_name, "type": "build"}]}
+    depends_config = {"kind": "stack", "depends": [input_name]}
     depends_file = os.path.join(element_dir, depends_name)
     _yaml.roundtrip_dump(depends_config, depends_file)
 
diff --git a/tests/frontend/strict-depends/elements/non-strict-depends.bst b/tests/frontend/strict-depends/elements/non-strict-depends.bst
index 9ab119bde..e0ed21ed6 100644
--- a/tests/frontend/strict-depends/elements/non-strict-depends.bst
+++ b/tests/frontend/strict-depends/elements/non-strict-depends.bst
@@ -1,4 +1,4 @@
 kind: stack
 
-build-depends:
+depends:
 - base.bst
diff --git a/tests/frontend/strict-depends/elements/strict-depends.bst b/tests/frontend/strict-depends/elements/strict-depends.bst
index 1e4e29414..10f3b9418 100644
--- a/tests/frontend/strict-depends/elements/strict-depends.bst
+++ b/tests/frontend/strict-depends/elements/strict-depends.bst
@@ -1,5 +1,5 @@
 kind: stack
 
-build-depends:
+depends:
 - filename: base.bst
   strict: true
diff --git a/tests/integration/project/elements/compose/test-integration.bst b/tests/integration/project/elements/compose/test-integration.bst
index 2f9faf170..ef47b3b58 100644
--- a/tests/integration/project/elements/compose/test-integration.bst
+++ b/tests/integration/project/elements/compose/test-integration.bst
@@ -1,6 +1,6 @@
 kind: stack
 
-runtime-depends:
+depends:
 - base.bst
 
 public: