Merge pull request #31290 from hashicorp/alisdair/check-block-missing-condition

configs: Fix check block configuration diagnostics

internal/configs/checks.go

@@ -40,7 +40,15 @@ type CheckRule struct {
 // is found.
 func (cr *CheckRule) validateSelfReferences(checkType string, addr addrs.Resource) hcl.Diagnostics {
 	var diags hcl.Diagnostics
-	refs, _ := lang.References(cr.Condition.Variables())
+	exprs := []hcl.Expression{
+		cr.Condition,
+		cr.ErrorMessage,
+	}
+	for _, expr := range exprs {
+		if expr == nil {
+			continue
+		}
+		refs, _ := lang.References(expr.Variables())
 		for _, ref := range refs {
 			var refAddr addrs.Resource
 
@@ -58,11 +66,12 @@ func (cr *CheckRule) validateSelfReferences(checkType string, addr addrs.Resourc
 					Severity: hcl.DiagError,
 					Summary:  fmt.Sprintf("Invalid reference in %s", checkType),
 					Detail:   fmt.Sprintf("Configuration for %s may not refer to itself.", addr.String()),
-				Subject:  cr.Condition.Range().Ptr(),
+					Subject:  expr.Range().Ptr(),
 				})
 				break
 			}
 		}
+	}
 	return diags
 }
 

internal/configs/testdata/invalid-files/precondition-postcondition-badref.tf

@@ -0,0 +1,29 @@
+data "example" "example" {
+  foo = 5
+
+  lifecycle {
+    precondition {
+      condition     = data.example.example.foo == 5 # ERROR: Invalid reference in precondition
+      error_message = "Must be five."
+    }
+    postcondition {
+      condition     = self.foo == 5
+      error_message = "Must be five, but is ${data.example.example.foo}." # ERROR: Invalid reference in postcondition
+    }
+  }
+}
+
+resource "example" "example" {
+  foo = 5
+
+  lifecycle {
+    precondition {
+      condition     = example.example.foo == 5 # ERROR: Invalid reference in precondition
+      error_message = "Must be five."
+    }
+    postcondition {
+      condition     = self.foo == 5
+      error_message = "Must be five, but is ${example.example.foo}." # ERROR: Invalid reference in postcondition
+    }
+  }
+}

internal/configs/testdata/invalid-files/precondition-postcondition-missing-condition.tf

@@ -0,0 +1,12 @@
+resource "example" "example" {
+  foo = 5
+
+  lifecycle {
+    precondition { # ERROR: Missing required argument
+      error_message = "Can a check block fail without a condition?"
+    }
+    postcondition { # ERROR: Missing required argument
+      error_message = "Do not try to pass the check; only realize that there is no check."
+    }
+  }
+}