fix internal template components link

internal/runtime/internal/controller/component_references.go

@@ -58,19 +58,23 @@ func ComponentReferences(cn dag.Node, g *dag.Graph, l log.Logger, scope *vm.Scop
 	refs := make([]Reference, 0, len(traversals))
 	for _, t := range traversals {
 
-		// TODO: fix this
-		if len(t) == 1 {
-			continue
-		}
-
 		ref, resolveDiags := resolveTraversal(t, g)
 		componentRefMatch := !resolveDiags.HasErrors()
 
 		// we look for a match in the provided scope and the stdlib
 		_, scopeMatch := scope.Lookup(t[0].Name)
 
 		if !componentRefMatch && !scopeMatch {
-			diags = append(diags, resolveDiags...)
+			// TODO: this workaround ignores the traversal errors inside of the foreach block
+			// We are currently using the traversal at the root level to access the references from outside of the foreach block.
+			// This is quite handy but not perfect because:
+			// - it fails with the var
+			// - it fails at the root level to link two components that are inside of the template (because they are not evaluated at the root level)
+			// Both cases should be ignored so in theory that works well but it's not pretty + it won't show real errors.
+			// So we need to find a different approach to traverse the foreach node.
+			if _, ok := cn.(*ForeachConfigNode); !ok {
+				diags = append(diags, resolveDiags...)
+			}
 			continue
 		}
 

internal/runtime/testdata/foreach/foreach_8.txtar

@@ -0,0 +1,23 @@
+Foreach with two components linked together.
+
+-- main.alloy --
+foreach "testForeach" {
+  collection = [10]
+  var = "num"
+
+  template {
+    testcomponents.passthrough "pt" {
+      input = num
+      lag = "1ms"
+    }
+    testcomponents.pulse "p" {
+      max = testcomponents.passthrough.pt.output
+      frequency = "10ms"
+      forward_to = [testcomponents.summation_receiver.sum.receiver]
+    }
+  }
+}
+
+// Similar to testcomponents.summation, but with a "receiver" export
+testcomponents.summation_receiver "sum" {
+}