_artifactcache.py: Raise ArtifactError() when quota size exceeds disk space.tristan/insufficient-storage-error

This is not an error related to loading data, like a parse error
in the quota specification is, but a problem raised by the artifact
cache - this allows us to assert more specific machine readable
errors in test cases (instead of checking the string in stderr, which
this patch also fixes).

This also removes a typo from the error message in the said error.

  * tests/artifactcache/cache_size.py

    Updated test case to expect the artifact error, which consequently
    changes the test case to properly assert a machine readable error
    instead of asserting text in the stderr (which is the real, secret
    motivation behind this patch).

  * tests/artifactcache/expiry.py: Reworked test_invalid_cache_quota()

    Now expect the artifact error for the tests which check configurations
    which create caches too large to fit on the disk.

3 files changed, 34 insertions, 26 deletions

diff --git a/buildstream/_artifactcache.py b/buildstream/_artifactcache.py
index 9ccbebade..b1afdf377 100644
--- a/buildstream/_artifactcache.py
+++ b/buildstream/_artifactcache.py
@@ -882,16 +882,16 @@ class ArtifactCache():
             else:
                 available = utils._pretty_size(available_space)
 
-            raise LoadError(LoadErrorReason.INVALID_DATA,
-                            ("Your system does not have enough available " +
-                             "space to support the cache quota specified.\n" +
-                             "\nYou have specified a quota of {quota} total disk space.\n" +
-                             "- The filesystem containing {local_cache_path} only " +
-                             "has: {available_size} available.")
-                            .format(
-                                quota=self.context.config_cache_quota,
-                                local_cache_path=self.context.artifactdir,
-                                available_size=available))
+            raise ArtifactError("Your system does not have enough available " +
+                                "space to support the cache quota specified.",
+                                detail=("You have specified a quota of {quota} total disk space.\n" +
+                                        "The filesystem containing {local_cache_path} only " +
+                                        "has {available_size} available.")
+                                .format(
+                                    quota=self.context.config_cache_quota,
+                                    local_cache_path=self.context.artifactdir,
+                                    available_size=available),
+                                reason='insufficient-storage-for-quota')
 
         # Place a slight headroom (2e9 (2GB) on the cache_quota) into
         # cache_quota to try and avoid exceptions.
diff --git a/tests/artifactcache/cache_size.py b/tests/artifactcache/cache_size.py
index 45c10d49a..11c8f6194 100644
--- a/tests/artifactcache/cache_size.py
+++ b/tests/artifactcache/cache_size.py
@@ -4,6 +4,7 @@ from unittest import mock
 
 from buildstream import _yaml
 from buildstream._artifactcache import CACHE_SIZE_FILE
+from buildstream._exceptions import ErrorDomain
 
 from tests.testutils import cli, create_element_size
 
@@ -86,5 +87,4 @@ def test_quota_over_1024T(cli, tmpdir):
 
     with volume_space_patch:
         result = cli.run(project, args=["build", "file.bst"])
-        failure_msg = 'Your system does not have enough available space to support the cache quota specified.'
-        assert failure_msg in result.stderr
+        result.assert_main_error(ErrorDomain.ARTIFACT, 'insufficient-storage-for-quota')
diff --git a/tests/artifactcache/expiry.py b/tests/artifactcache/expiry.py
index 4c47ef75c..1292e50ea 100644
--- a/tests/artifactcache/expiry.py
+++ b/tests/artifactcache/expiry.py
@@ -304,20 +304,28 @@ def test_never_delete_required_track(cli, datafiles, tmpdir):
 
 # Ensure that only valid cache quotas make it through the loading
 # process.
-@pytest.mark.parametrize("quota,success", [
-    ("1", True),
-    ("1K", True),
-    ("50%", True),
-    ("infinity", True),
-    ("0", True),
-    ("-1", False),
-    ("pony", False),
-    ("7K", False),
-    ("70%", False),
-    ("200%", False)
+#
+# This test virtualizes the condition to assume a storage volume
+# has 10K total disk space, and 6K of it is already in use (not
+# including any space used by the artifact cache).
+#
+@pytest.mark.parametrize("quota,err_domain,err_reason", [
+    # Valid configurations
+    ("1", 'success', None),
+    ("1K", 'success', None),
+    ("50%", 'success', None),
+    ("infinity", 'success', None),
+    ("0", 'success', None),
+    # Invalid configurations
+    ("-1", ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA),
+    ("pony", ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA),
+    ("200%", ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA),
+    # Not enough space for these caches
+    ("7K", ErrorDomain.ARTIFACT, 'insufficient-storage-for-quota'),
+    ("70%", ErrorDomain.ARTIFACT, 'insufficient-storage-for-quota')
 ])
 @pytest.mark.datafiles(DATA_DIR)
-def test_invalid_cache_quota(cli, datafiles, tmpdir, quota, success):
+def test_invalid_cache_quota(cli, datafiles, tmpdir, quota, err_domain, err_reason):
     project = os.path.join(datafiles.dirname, datafiles.basename)
     os.makedirs(os.path.join(project, 'elements'))
 
@@ -356,10 +364,10 @@ def test_invalid_cache_quota(cli, datafiles, tmpdir, quota, success):
     with volume_space_patch, cache_size_patch:
         res = cli.run(project=project, args=['workspace', 'list'])
 
-    if success:
+    if err_domain == 'success':
         res.assert_success()
     else:
-        res.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA)
+        res.assert_main_error(err_domain, err_reason)
 
 
 @pytest.mark.datafiles(DATA_DIR)