Add bats integration test for dependency failure tree

Author: kindermax

tests/dependency_failure_tree.bats

@@ -0,0 +1,23 @@
+load test_helpers
+
+setup() {
+    load "${BATS_UTILS_PATH}/bats-support/load.bash"
+    load "${BATS_UTILS_PATH}/bats-assert/load.bash"
+    cd ./tests/dependency_failure_tree
+}
+
+@test "dependency_failure_tree: shows full 3-level chain on failure" {
+    run env NO_COLOR=1 lets deploy
+    assert_failure
+    assert_line --index 0 "  deploy"
+    assert_line --index 1 "    build"
+    assert_line --index 2 --partial "      lint"
+    assert_line --index 2 --partial "failed here"
+}
+
+@test "dependency_failure_tree: single node when no depends" {
+    run env NO_COLOR=1 lets lint
+    assert_failure
+    assert_line --index 0 --partial "  lint"
+    assert_line --index 0 --partial "failed here"
+}

tests/dependency_failure_tree/lets.yaml

@@ -0,0 +1,10 @@
+shell: bash
+commands:
+  deploy:
+    depends: [build]
+    cmd: echo done
+  build:
+    depends: [lint]
+    cmd: echo done
+  lint:
+    cmd: exit 1