Add tests and fix arguments with multiple values

src/main/resources/io/viash/runners/nextflow/workflowFactory/workflowFactory.nf

@@ -10,7 +10,8 @@ def _debug(workflowArgs, debugKey) {
 def workflowFactory(Map args, Map defaultWfArgs, Map meta) {
   def workflowArgs = processWorkflowArgs(args, defaultWfArgs, meta)
   def key_ = workflowArgs["key"]
-
+  def multipleArgs = meta.config.allArguments.findAll{ it.multiple }.collect{it.plainName}
+
   workflow workflowInstance {
     take: input_
 
@@ -195,7 +196,7 @@ def workflowFactory(Map args, Map defaultWfArgs, Map meta) {
       // | view{"chInitialOutput: ${it.take(3)}"}
 
     // join the output [prev_id, new_id, output] with the previous state [prev_id, state, ...]
-    def chPublishWithPreviousState = safeJoin(chInitialOutputProcessed, chModifiedFiltered, key_)
+    def chPublishWithPreviousState = safeJoin(chInitialOutputProcessed, chRunFiltered, key_)
       // input tuple format: [join_id, id, output, prev_state, ...]
       // output tuple format: [join_id, id, new_state, ...]
       | map{ tup ->
@@ -222,13 +223,26 @@ def workflowFactory(Map args, Map defaultWfArgs, Map meta) {
       | groupTuple(by: 1, sort: 'hash', size: chInitialOutputList.size(), remainder: true)
       | map {join_ids, id, states ->
         def newJoinId = join_ids.unique{a, b -> a <=> b}
-        assert newJoinId.size() == 1: "Multiple join IDs were emitted for '$id'."
+        assert newJoinId.size() == 1: "Multiple events were emitted for '$id'."
         def newJoinIdUnique = newJoinId[0]
         def newState = states.inject([:]){ old_state, state_to_add ->
-          def overlap = old_state.keySet().intersect(state_to_add.keySet())
-          assert overlap.isEmpty() : "ID $id: multiple entries for for argument(s) $overlap were emitted."
-          def return_state = old_state + state_to_add
-          return return_state 
+          def stateToAddNoMultiple = state_to_add.findAll{k, v -> !multipleArgs.contains(k)}
+          // First add non multiple arguments
+
+          def overlap = old_state.keySet().intersect(stateToAddNoMultiple.keySet())
+          assert overlap.isEmpty() : "ID $id: multiple entries for " + 
+            " argument(s) $overlap were emitted."
+          def return_state = old_state + stateToAddNoMultiple
+
+          // Add `multiple: true` arguments
+          def stateToAddMultiple = state_to_add.findAll{k, v -> multipleArgs.contains(k)}
+          stateToAddMultiple.each {k, v ->
+            def currentKey = return_state.getOrDefault(k, [])
+            def currentKeyList = currentKey instanceof List ? currentKey : [currentKey]
+            currentKeyList.add(v)
+            return_state[k] = currentKeyList
+          }
+          return return_state
         }
 
         // simplify output if need be

src/test/resources/testnextflowvdsl3/src/multiple_emit_channels/config.vsh.yaml

@@ -0,0 +1,27 @@
+name: multiple_emit_channels
+namespace: test_wfs
+argument_groups:
+  - name: Outputs
+    arguments:
+      - name: "--input"
+        type: file
+        description: Input file
+        required: true
+        example: input.txt
+      - name: "--step_1_output"
+        required: true
+        type: file
+        direction: output
+      - name: "--step_2_output"
+        required: true
+        type: file
+        direction: output
+resources:
+  - type: nextflow_script
+    path: main.nf
+    entrypoint: base
+dependencies:
+  - name: step1
+  - name: step3
+platforms:
+  - type: nextflow

src/test/resources/testnextflowvdsl3/src/multiple_emit_channels/main.nf

@@ -0,0 +1,22 @@
+workflow base {
+  take: input_ch
+  main:
+
+    step_1_ch = input_ch
+    // test fromstate and tostate with list[string]
+    | step1.run(
+      fromState: ["input"],
+      toState: { id, output, state -> ["step_1_output": output.output] }
+    )
+
+    step_2_ch = input_ch
+    // test fromstate and tostate with map[string, string]
+    | step3.run(
+      fromState: ["input"],
+      toState: { id, output, state -> ["step_3_output": output.output] }
+    )
+
+  emit:
+    step_1_ch
+    step_3_ch
+}