Add extended action validation during config parsing

- Verify that actions and linked_resources are in the current module
- Verify that given traversals reference the right types (action, resource)
- Add some validation tests

Things not captured in config validation:
- is this action referencing a resource defined in this configuration
- is this resource referencing an action defined in this configuration

Todo:
- Verify actions and resources are specific instances - no containers/expansion allowed in referenfces for now

Author: mildwonkey

internal/configs/action.go

@@ -123,6 +123,7 @@ func decodeActionTriggerBlock(block *hcl.Block) (*ActionTrigger, hcl.Diagnostics
 					Detail:   "The \"event\" argument supports the following values: before_create, after_create, before_update, after_update, before_destroy, after_destroy.",
 					Subject:  expr.Range().Ptr(),
 				})
+				continue
 			}
 
 			if event == BeforeDestroy || event == AfterDestroy {
@@ -132,8 +133,8 @@ func decodeActionTriggerBlock(block *hcl.Block) (*ActionTrigger, hcl.Diagnostics
 					Detail:   "The destroy events (before_destroy, after_destroy) are not supported as of right now. They will be supported in a future release.",
 					Subject:  expr.Range().Ptr(),
 				})
+				continue
 			}
-
 			events = append(events, event)
 		}
 		a.Events = events
@@ -146,25 +147,29 @@ func decodeActionTriggerBlock(block *hcl.Block) (*ActionTrigger, hcl.Diagnostics
 		for _, expr := range exprs {
 			traversal, travDiags := hcl.AbsTraversalForExpr(expr)
 			diags = append(diags, travDiags...)
-			// verify that the traversal is an action
-			if traversal.RootName() != "action" {
-				diags = append(diags, &hcl.Diagnostic{
-					Severity: hcl.DiagError,
-					Summary:  "Invalid actions argument inside action_triggers",
-					Detail:   "action_triggers.actions accepts a list of one or more actions",
-					Subject:  block.DefRange.Ptr(),
-				})
-				continue
-			}
 
-			if len(traversal) != 0 {
-				actionRef := ActionRef{
-					Traversal: traversal,
-					Range:     expr.Range(),
+			if len(traversal) > 0 {
+				// verify that the traversal is an action
+				ref, refDiags := addrs.ParseRef(traversal)
+				diags = append(diags, refDiags.ToHCL()...)
+
+				switch ref.Subject.(type) {
+				case addrs.ActionInstance, addrs.Action:
+					actionRef := ActionRef{
+						Traversal: traversal,
+						Range:     expr.Range(),
+					}
+					actions = append(actions, actionRef)
+				default:
+					diags = append(diags, &hcl.Diagnostic{
+						Severity: hcl.DiagError,
+						Summary:  "Invalid actions argument inside action_triggers",
+						Detail:   "action_triggers.actions accepts a list of one or more actions, which must be in the current module.",
+						Subject:  expr.Range().Ptr(),
+					})
+					continue
 				}
-				actions = append(actions, actionRef)
 			}
-
 		}
 		a.Actions = actions
 	}

internal/configs/action_test.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hcltest"
+	"github.com/zclconf/go-cty/cty"
 )
 
 func TestDecodeActionBlock(t *testing.T) {
@@ -125,6 +126,129 @@ func TestDecodeActionBlock(t *testing.T) {
 	}
 }
 
+func TestDecodeActionTriggerBlock(t *testing.T) {
+	conditionExpr := hcltest.MockExprLiteral(cty.True)
+	eventsListExpr := hcltest.MockExprList([]hcl.Expression{hcltest.MockExprTraversalSrc("after_create"), hcltest.MockExprTraversalSrc("after_update")})
+
+	fooActionExpr := hcltest.MockExprTraversalSrc("action.action_type.foo")
+	barActionExpr := hcltest.MockExprTraversalSrc("action.action_type.bar")
+	fooAndBarExpr := hcltest.MockExprList([]hcl.Expression{fooActionExpr, barActionExpr})
+
+	// bad inputs!
+	moduleActionExpr := hcltest.MockExprTraversalSrc("module.foo.action.action_type.bar")
+	fooDataSourceExpr := hcltest.MockExprTraversalSrc("data.example.foo")
+
+	tests := map[string]struct {
+		input       *hcl.Block
+		want        *ActionTrigger
+		expectDiags []string
+	}{
+		"simple example": {
+			&hcl.Block{
+				Type: "action_trigger",
+				Body: hcltest.MockBody(&hcl.BodyContent{
+					Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+						"condition": conditionExpr,
+						"events":    eventsListExpr,
+						"actions":   fooAndBarExpr,
+					}),
+				}),
+			},
+			&ActionTrigger{
+				Condition: conditionExpr,
+				Events:    []ActionTriggerEvent{AfterCreate, AfterUpdate},
+				Actions: []ActionRef{
+					{
+						mustAbsTraversalForExpr(fooActionExpr),
+						fooActionExpr.Range(),
+					},
+					{
+						mustAbsTraversalForExpr(barActionExpr),
+						barActionExpr.Range(),
+					},
+				},
+			},
+			nil,
+		},
+		"error - referencing actions in other modules": {
+			&hcl.Block{
+				Type: "action_trigger",
+				Body: hcltest.MockBody(&hcl.BodyContent{
+					Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+						"condition": conditionExpr,
+						"events":    eventsListExpr,
+						"actions":   hcltest.MockExprList([]hcl.Expression{moduleActionExpr}),
+					}),
+				}),
+			},
+			&ActionTrigger{
+				Condition: conditionExpr,
+				Events:    []ActionTriggerEvent{AfterCreate, AfterUpdate},
+				Actions:   []ActionRef{},
+			},
+			[]string{
+				"MockExprTraversal:0,0-33: Invalid actions argument inside action_triggers; action_triggers.actions accepts a list of one or more actions, which must be in the current module.",
+				":0,0-0: No actions specified; At least one action must be specified for an action_trigger.",
+			},
+		},
+		"error - action is not an action": {
+			&hcl.Block{
+				Type: "action_trigger",
+				Body: hcltest.MockBody(&hcl.BodyContent{
+					Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+						"condition": conditionExpr,
+						"events":    eventsListExpr,
+						"actions":   hcltest.MockExprList([]hcl.Expression{fooDataSourceExpr}),
+					}),
+				}),
+			},
+			&ActionTrigger{
+				Condition: conditionExpr,
+				Events:    []ActionTriggerEvent{AfterCreate, AfterUpdate},
+				Actions:   []ActionRef{},
+			},
+			[]string{
+				"MockExprTraversal:0,0-16: Invalid actions argument inside action_triggers; action_triggers.actions accepts a list of one or more actions, which must be in the current module.",
+				":0,0-0: No actions specified; At least one action must be specified for an action_trigger.",
+			},
+		},
+		"error - invalid event": {
+			&hcl.Block{
+				Type: "action_trigger",
+				Body: hcltest.MockBody(&hcl.BodyContent{
+					Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+						"condition": conditionExpr,
+						"events":    hcltest.MockExprList([]hcl.Expression{hcltest.MockExprTraversalSrc("not_an_event")}),
+						"actions":   hcltest.MockExprList([]hcl.Expression{fooActionExpr}),
+					}),
+				}),
+			},
+			&ActionTrigger{
+				Condition: conditionExpr,
+				Events:    []ActionTriggerEvent{},
+				Actions: []ActionRef{
+					{
+						mustAbsTraversalForExpr(fooActionExpr),
+						fooActionExpr.Range(),
+					},
+				},
+			},
+			[]string{
+				"MockExprTraversal:0,0-12: Invalid \"event\" value not_an_event; The \"event\" argument supports the following values: before_create, after_create, before_update, after_update, before_destroy, after_destroy.",
+				":0,0-0: No events specified; At least one event must be specified for an action_trigger.",
+			},
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			got, diags := decodeActionTriggerBlock(test.input)
+			assertExactDiagnostics(t, diags, test.expectDiags)
+			assertResultDeepEqual(t, got, test.want)
+		})
+	}
+}
+
 func mustAbsTraversalForExpr(expr hcl.Expression) hcl.Traversal {
 	trav, diags := hcl.AbsTraversalForExpr(expr)
 	if diags.HasErrors() {