add test for scatter in loop (#1965)

tests/loop/scatter-inside-loop.cwl

@@ -0,0 +1,53 @@
+#!/usr/bin/env cwl-runner
+cwlVersion: v1.2
+class: Workflow
+$namespaces:
+  cwltool: "http://commonwl.org/cwltool#"
+requirements:
+  InlineJavascriptRequirement: {}
+  ScatterFeatureRequirement: {}
+  SubworkflowFeatureRequirement: {}
+inputs:
+  i1: int[]
+  i2: int
+outputs:
+  o1:
+    type: int[]
+    outputSource: scatter/o1
+steps:
+  scatter:
+    run:
+      class: Workflow
+      inputs:
+        i1: int[]
+        i2: int
+      outputs:
+        o1:
+          type: int[]
+          outputSource: subworkflow/o1
+      steps:
+        subworkflow:
+          run:
+            class: ExpressionTool
+            inputs:
+              i1: int
+              i2: int
+            outputs:
+              o1: int
+            expression: >
+              ${return {'o1': inputs.i1 + inputs.i2};}
+          in:
+            i1: i1
+            i2: i2
+          out: [o1]
+          scatter: i1
+    in:
+      i1: i1
+      i2: i2
+    out: [o1]
+    requirements:
+      cwltool:Loop:
+        loopWhen: $(inputs.i1[0] < 10)
+        loop:
+          i1: o1
+        outputMethod: last

tests/test_loop.py

@@ -221,6 +221,19 @@ def test_loop_inside_scatter() -> None:
     assert json.loads(stream.getvalue()) == expected
 
 
+def test_scatter_inside_loop() -> None:
+    """Test a loop workflow with inside a scatter step."""
+    stream = StringIO()
+    params = [
+        "--enable-ext",
+        get_data("tests/loop/scatter-inside-loop.cwl"),
+        get_data("tests/loop/loop-inside-scatter-job.yml"),
+    ]
+    main(params, stdout=stream)
+    expected = {"o1": [10, 11, 12, 13, 14]}
+    assert json.loads(stream.getvalue()) == expected
+
+
 def test_nested_loops() -> None:
     """Test a workflow with two nested loops."""
     stream = StringIO()