diff --git a/tests/loader/junctions.py b/tests/loader/junctions.py
index 66c232b67f0dbf91cda97073981bf3c6850334e5..3495946e19d1c4aa0800a0b06fcd6c79f2948bde 100644
--- a/tests/loader/junctions.py
+++ b/tests/loader/junctions.py
@@ -3,7 +3,7 @@ import pytest
 import shutil
 
 from buildstream import _yaml, ElementError
-from buildstream._exceptions import LoadError, LoadErrorReason
+from buildstream._exceptions import ErrorDomain, LoadErrorReason
 from tests.testutils import cli, create_repo
 from tests.testutils.site import HAVE_GIT
 
@@ -38,9 +38,9 @@ def test_simple_build(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that the checkout contains the expected files from both projects
     assert(os.path.exists(os.path.join(checkoutdir, 'base.txt')))
@@ -54,7 +54,7 @@ def test_build_of_same_junction_used_twice(cli, tmpdir, datafiles):
     # Check we can build a project that contains the same junction
     # that is used twice, but named differently
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
 
 
 @pytest.mark.datafiles(DATA_DIR)
@@ -69,9 +69,9 @@ def test_nested_simple(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that the checkout contains the expected files from all subprojects
     assert(os.path.exists(os.path.join(checkoutdir, 'base.txt')))
@@ -93,9 +93,9 @@ def test_nested_double(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that the checkout contains the expected files from all subprojects
     assert(os.path.exists(os.path.join(checkoutdir, 'base.txt')))
@@ -115,10 +115,7 @@ def test_nested_conflict(cli, datafiles):
     copy_subprojects(project, datafiles, ['foo', 'bar'])
 
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code != 0
-    assert result.exception
-    assert isinstance(result.exception, LoadError)
-    assert result.exception.reason == LoadErrorReason.CONFLICTING_JUNCTION
+    result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.CONFLICTING_JUNCTION)
 
 
 @pytest.mark.datafiles(DATA_DIR)
@@ -126,10 +123,7 @@ def test_invalid_missing(cli, datafiles):
     project = os.path.join(str(datafiles), 'invalid')
 
     result = cli.run(project=project, args=['build', 'missing.bst'])
-    assert result.exit_code != 0
-    assert result.exception
-    assert isinstance(result.exception, LoadError)
-    assert result.exception.reason == LoadErrorReason.MISSING_FILE
+    result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.MISSING_FILE)
 
 
 @pytest.mark.datafiles(DATA_DIR)
@@ -138,10 +132,7 @@ def test_invalid_with_deps(cli, datafiles):
     copy_subprojects(project, datafiles, ['base'])
 
     result = cli.run(project=project, args=['build', 'junction-with-deps.bst'])
-    assert result.exit_code != 0
-    assert result.exception
-    assert isinstance(result.exception, ElementError)
-    assert result.exception.reason == 'element-forbidden-depends'
+    result.assert_main_error(ErrorDomain.ELEMENT, 'element-forbidden-depends')
 
 
 @pytest.mark.datafiles(DATA_DIR)
@@ -150,10 +141,7 @@ def test_invalid_junction_dep(cli, datafiles):
     copy_subprojects(project, datafiles, ['base'])
 
     result = cli.run(project=project, args=['build', 'junction-dep.bst'])
-    assert result.exit_code != 0
-    assert result.exception
-    assert isinstance(result.exception, LoadError)
-    assert result.exception.reason == LoadErrorReason.INVALID_DATA
+    result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.INVALID_DATA)
 
 
 @pytest.mark.datafiles(DATA_DIR)
@@ -165,9 +153,9 @@ def test_options_default(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     assert(os.path.exists(os.path.join(checkoutdir, 'pony.txt')))
     assert(not os.path.exists(os.path.join(checkoutdir, 'horsy.txt')))
@@ -182,9 +170,9 @@ def test_options(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     assert(not os.path.exists(os.path.join(checkoutdir, 'pony.txt')))
     assert(os.path.exists(os.path.join(checkoutdir, 'horsy.txt')))
@@ -199,9 +187,9 @@ def test_options_inherit(cli, tmpdir, datafiles):
 
     # Build, checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     assert(not os.path.exists(os.path.join(checkoutdir, 'pony.txt')))
     assert(os.path.exists(os.path.join(checkoutdir, 'horsy.txt')))
@@ -228,14 +216,11 @@ def test_git_show(cli, tmpdir, datafiles):
 
     # Verify that bst show does not implicitly fetch subproject
     result = cli.run(project=project, args=['show', 'target.bst'])
-    assert result.exit_code != 0
-    assert result.exception
-    assert isinstance(result.exception, LoadError)
-    assert result.exception.reason == LoadErrorReason.SUBPROJECT_FETCH_NEEDED
+    result.assert_main_error(ErrorDomain.LOAD, LoadErrorReason.SUBPROJECT_FETCH_NEEDED)
 
     # Explicitly fetch subproject
     result = cli.run(project=project, args=['source', 'fetch', 'base.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that bst show succeeds now and the pipeline includes the subproject element
     element_list = cli.get_pipeline(project, ['target.bst'])
@@ -263,9 +248,9 @@ def test_git_build(cli, tmpdir, datafiles):
 
     # Build (with implicit fetch of subproject), checkout
     result = cli.run(project=project, args=['build', 'target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that the checkout contains the expected files from both projects
     assert(os.path.exists(os.path.join(checkoutdir, 'base.txt')))
@@ -304,9 +289,9 @@ def test_build_git_cross_junction_names(cli, tmpdir, datafiles):
 
     # Build (with implicit fetch of subproject), checkout
     result = cli.run(project=project, args=['build', 'base.bst:target.bst'])
-    assert result.exit_code == 0
+    result.assert_success()
     result = cli.run(project=project, args=['checkout', 'base.bst:target.bst', checkoutdir])
-    assert result.exit_code == 0
+    result.assert_success()
 
     # Check that the checkout contains the expected files from both projects
     assert(os.path.exists(os.path.join(checkoutdir, 'base.txt')))