Reword scope errors to clarify behavior

src/Bicep.Core.IntegrationTests/NestedResourceTests.cs

@@ -785,7 +785,7 @@ public void Nested_resource_blocks_existing_parents_at_different_scopes(string p
 ");
 
             result.Diagnostics.ExcludingLinterDiagnostics().ExcludingMissingTypes().Should().HaveDiagnostics(new[] {
-                ("BCP165", DiagnosticLevel.Error, "Cannot deploy a resource with ancestor under a different scope. Resource \"res1\" has the \"scope\" property set."),
+                ("BCP165", DiagnosticLevel.Error, "A resource's computed scope must match that of the Bicep file for it to be deployable. This resource's scope is computed from the \"scope\" property value assigned to ancestor resource \"res1\". You must use modules to deploy resources to a different scope."),
             });
         }
 
@@ -830,7 +830,7 @@ public void Nested_resource_blocks_scope_on_child_resources()
             {
                 template.Should().NotHaveValue();
                 diags.ExcludingLinterDiagnostics().ExcludingMissingTypes().Should().HaveDiagnostics(new[] {
-                  ("BCP164", DiagnosticLevel.Error, "The \"scope\" property is unsupported for a resource with a parent resource. This resource has \"res2\" declared as its parent."),
+                  ("BCP164", DiagnosticLevel.Error, "A child resource's scope is computed based on the scope of its ancestor resource. This means that using the \"scope\" property on a child resource is unsupported."),
                 });
             }
         }

src/Bicep.Core.IntegrationTests/ParentPropertyResourceTests.cs

@@ -210,7 +210,7 @@ public void Parent_property_blocks_existing_parents_at_different_scopes(string p
 ");
 
             result.Diagnostics.ExcludingLinterDiagnostics().ExcludingMissingTypes().Should().HaveDiagnostics(new[] {
-                ("BCP165", DiagnosticLevel.Error, "Cannot deploy a resource with ancestor under a different scope. Resource \"res1\" has the \"scope\" property set."),
+                ("BCP165", DiagnosticLevel.Error, "A resource's computed scope must match that of the Bicep file for it to be deployable. This resource's scope is computed from the \"scope\" property value assigned to ancestor resource \"res1\". You must use modules to deploy resources to a different scope."),
             });
         }
 
@@ -257,7 +257,7 @@ public void Parent_property_blocks_scope_on_child_resources()
             {
                 template.Should().NotHaveValue();
                 diags.ExcludingLinterDiagnostics().ExcludingMissingTypes().Should().HaveDiagnostics(new[] {
-                  ("BCP164", DiagnosticLevel.Error, "The \"scope\" property is unsupported for a resource with a parent resource. This resource has \"res2\" declared as its parent."),
+                  ("BCP164", DiagnosticLevel.Error, "A child resource's scope is computed based on the scope of its ancestor resource. This means that using the \"scope\" property on a child resource is unsupported."),
                 });
             }
         }

src/Bicep.Core.IntegrationTests/ScenarioTests.cs

@@ -695,9 +695,9 @@ param groupReaderId string
 
             result.Template.Should().NotHaveValue();
             result.ExcludingLinterDiagnostics().Should().HaveDiagnostics(new[] {
-                ("BCP139", DiagnosticLevel.Error, "The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module."),
-                ("BCP139", DiagnosticLevel.Error, "The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module."),
-                ("BCP139", DiagnosticLevel.Error, "The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module."),
+                ("BCP139", DiagnosticLevel.Error, "A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope."),
+                ("BCP139", DiagnosticLevel.Error, "A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope."),
+                ("BCP139", DiagnosticLevel.Error, "A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope."),
             });
         }
 

src/Bicep.Core.IntegrationTests/ScopeTests.cs

@@ -276,7 +276,7 @@ public void Errors_are_raised_for_extensions_of_existing_resources_at_invalid_sc
 "));
 
             diags.Should().HaveDiagnostics(new[] {
-                ("BCP139", DiagnosticLevel.Error, "The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module."),
+                ("BCP139", DiagnosticLevel.Error, "A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope."),
             });
         }
 

src/Bicep.Core.Samples/Files/InvalidResources_CRLF/main.diagnostics.bicep

@@ -1390,7 +1390,7 @@ resource invalidScope3 'My.Rp/mockResource@2020-12-01' = {
 //@[23:54) [BCP081 (Warning)] Resource type "My.Rp/mockResource@2020-12-01" does not have types available. (CodeDescription: none) |'My.Rp/mockResource@2020-12-01'|
   name: 'invalidScope3'
   scope: subscription()
-//@[9:23) [BCP139 (Error)] The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module. (CodeDescription: none) |subscription()|
+//@[9:23) [BCP139 (Error)] A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope. (CodeDescription: none) |subscription()|
 }
 
 resource invalidDuplicateName1 'Mock.Rp/mockResource@2020-01-01' = {
@@ -1854,7 +1854,7 @@ resource p1_res1 'Microsoft.Rp1/resource1@2020-06-01' existing = {
 
 resource p1_child1 'Microsoft.Rp1/resource1/child1@2020-06-01' = {
 //@[19:62) [BCP081 (Warning)] Resource type "Microsoft.Rp1/resource1/child1@2020-06-01" does not have types available. (CodeDescription: none) |'Microsoft.Rp1/resource1/child1@2020-06-01'|
-//@[65:106) [BCP165 (Error)] Cannot deploy a resource with ancestor under a different scope. Resource "p1_res1" has the "scope" property set. (CodeDescription: none) |{\r\n  parent: p1_res1\r\n  name: 'child1'\r\n}|
+//@[65:106) [BCP165 (Error)] A resource's computed scope must match that of the Bicep file for it to be deployable. This resource's scope is computed from the "scope" property value assigned to ancestor resource "p1_res1". You must use modules to deploy resources to a different scope. (CodeDescription: none) |{\r\n  parent: p1_res1\r\n  name: 'child1'\r\n}|
   parent: p1_res1
   name: 'child1'
 }
@@ -1874,7 +1874,7 @@ resource p2_res2 'Microsoft.Rp2/resource2@2020-06-01' = {
 resource p2_res2child 'Microsoft.Rp2/resource2/child2@2020-06-01' = {
 //@[22:65) [BCP081 (Warning)] Resource type "Microsoft.Rp2/resource2/child2@2020-06-01" does not have types available. (CodeDescription: none) |'Microsoft.Rp2/resource2/child2@2020-06-01'|
   scope: p2_res1
-//@[9:16) [BCP164 (Error)] The "scope" property is unsupported for a resource with a parent resource. This resource has "p2_res2" declared as its parent. (CodeDescription: none) |p2_res1|
+//@[9:16) [BCP164 (Error)] A child resource's scope is computed based on the scope of its ancestor resource. This means that using the "scope" property on a child resource is unsupported. (CodeDescription: none) |p2_res1|
   parent: p2_res2
   name: 'child2'
 }

src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs

@@ -868,7 +868,7 @@ public Diagnostic RuntimeValueNotAllowedInProperty(string propertyName, string?
                 TextSpan,
                 DiagnosticLevel.Error,
                 "BCP139",
-                $"The root resource scope must match that of the Bicep file. To deploy a resource to a different root scope, use a module.");
+                $"A resource's scope must match the scope of the Bicep file for it to be deployable. You must use modules to deploy resources to a different scope.");
 
             public ErrorDiagnostic UnterminatedMultilineString() => new(
                 TextSpan,
@@ -988,12 +988,12 @@ public Diagnostic RuntimeValueNotAllowedInProperty(string propertyName, string?
             public ErrorDiagnostic ScopeUnsupportedOnChildResource(string parentIdentifier) => new(
                 TextSpan,
                 "BCP164",
-                $"The \"{LanguageConstants.ResourceScopePropertyName}\" property is unsupported for a resource with a parent resource. This resource has \"{parentIdentifier}\" declared as its parent.");
+                $"A child resource's scope is computed based on the scope of its ancestor resource. This means that using the \"{LanguageConstants.ResourceScopePropertyName}\" property on a child resource is unsupported.");
 
             public ErrorDiagnostic ScopeDisallowedForAncestorResource(string ancestorIdentifier) => new(
                 TextSpan,
                 "BCP165",
-                $"Cannot deploy a resource with ancestor under a different scope. Resource \"{ancestorIdentifier}\" has the \"{LanguageConstants.ResourceScopePropertyName}\" property set.");
+                $"A resource's computed scope must match that of the Bicep file for it to be deployable. This resource's scope is computed from the \"{LanguageConstants.ResourceScopePropertyName}\" property value assigned to ancestor resource \"{ancestorIdentifier}\". You must use modules to deploy resources to a different scope.");
 
             public ErrorDiagnostic DuplicateDecorator(string decoratorName) => new(
                 TextSpan,