Updates diagnostics handling for appsync

Author: gdavison

.ci/semgrep/pluginsdk/diags.yml

@@ -5,7 +5,6 @@ rules:
     message: Prefer `sdkdiag.AppendFromErr` to `diag.FromErr`
     paths:
       exclude:
-        - internal/service/appsync
         - internal/service/[b-z]*
     patterns:
       - pattern: diag.FromErr($ERR)
@@ -19,7 +18,6 @@ rules:
     message: Prefer `sdkdiag.AppendErrorf` to `diag.Errorf`
     paths:
       exclude:
-        - internal/service/appsync
         - internal/service/[b-z]*
     patterns:
       - pattern: diag.Errorf(...)
@@ -33,7 +31,6 @@ rules:
     message: Append results of $READFN to diags instead of returning directly
     paths:
       exclude:
-        - internal/service/appsync
         - internal/service/[b-z]*
     patterns:
       - pattern: return $READFN(...)
@@ -52,7 +49,6 @@ rules:
       include:
         - internal/service
       exclude:
-        - internal/service/appsync
         - internal/service/[b-z]*
     patterns:
       - pattern: return nil

internal/service/appsync/graphql_api.go

@@ -339,11 +339,11 @@ func resourceGraphQLAPIRead(ctx context.Context, d *schema.ResourceData, meta in
 	if !d.IsNewResource() && tfresource.NotFound(err) {
 		log.Printf("[WARN] AppSync GraphQL API (%s) not found, removing from state", d.Id())
 		d.SetId("")
-		return nil
+		return diags
 	}
 
 	if err != nil {
-		return diag.Errorf("reading AppSync GraphQL API (%s): %s", d.Id(), err)
+		return sdkdiag.AppendErrorf(diags, "reading AppSync GraphQL API (%s): %s", d.Id(), err)
 	}
 
 	if err := d.Set("additional_authentication_provider", flattenGraphQLAPIAdditionalAuthenticationProviders(api.AdditionalAuthenticationProviders)); err != nil {