core: "Did you mean" hints for unsupported resource types

When we detect that a module is trying to declare a resource type that
doesn't exist in its corresponding provider, we have enough information to
give some hints as to what might be wrong.

We give preference to the possibility of mixing up a managed resource type
with a data resource type, but if not that then we'll use our usual
levenshtein-distance-based similar name suggestion function.

We currently don't typically test exact error message text, so and this is
just a cosmetic change to the message output, so there are now new tests
or test modifications here.

terraform/node_resource_validate.go

@@ -7,6 +7,7 @@ import (
 	"github.com/hashicorp/terraform/addrs"
 	"github.com/hashicorp/terraform/configs"
 	"github.com/hashicorp/terraform/configs/configschema"
+	"github.com/hashicorp/terraform/internal/didyoumean"
 	"github.com/hashicorp/terraform/providers"
 	"github.com/hashicorp/terraform/provisioners"
 	"github.com/hashicorp/terraform/tfdiags"
@@ -345,10 +346,23 @@ func (n *NodeValidatableResource) validateResource(ctx EvalContext) tfdiags.Diag
 	case addrs.ManagedResourceMode:
 		schema, _ := providerSchema.SchemaForResourceType(n.Config.Mode, n.Config.Type)
 		if schema == nil {
+			var suggestion string
+			if dSchema, _ := providerSchema.SchemaForResourceType(addrs.DataResourceMode, n.Config.Type); dSchema != nil {
+				suggestion = fmt.Sprintf("\n\nDid you intend to use the data source %q? If so, declare this using a \"data\" block instead of a \"resource\" block.", n.Config.Type)
+			} else if len(providerSchema.ResourceTypes) > 0 {
+				suggestions := make([]string, 0, len(providerSchema.ResourceTypes))
+				for name := range providerSchema.ResourceTypes {
+					suggestions = append(suggestions, name)
+				}
+				if suggestion = didyoumean.NameSuggestion(n.Config.Type, suggestions); suggestion != "" {
+					suggestion = fmt.Sprintf(" Did you mean %q?", suggestion)
+				}
+			}
+
 			diags = diags.Append(&hcl.Diagnostic{
 				Severity: hcl.DiagError,
 				Summary:  "Invalid resource type",
-				Detail:   fmt.Sprintf("The provider %s does not support resource type %q.", n.Config.ProviderConfigAddr(), n.Config.Type),
+				Detail:   fmt.Sprintf("The provider %s does not support resource type %q.%s", n.Provider().ForDisplay(), n.Config.Type, suggestion),
 				Subject:  &n.Config.TypeRange,
 			})
 			return diags
@@ -386,10 +400,23 @@ func (n *NodeValidatableResource) validateResource(ctx EvalContext) tfdiags.Diag
 	case addrs.DataResourceMode:
 		schema, _ := providerSchema.SchemaForResourceType(n.Config.Mode, n.Config.Type)
 		if schema == nil {
+			var suggestion string
+			if dSchema, _ := providerSchema.SchemaForResourceType(addrs.ManagedResourceMode, n.Config.Type); dSchema != nil {
+				suggestion = fmt.Sprintf("\n\nDid you intend to use the managed resource type %q? If so, declare this using a \"resource\" block instead of a \"data\" block.", n.Config.Type)
+			} else if len(providerSchema.DataSources) > 0 {
+				suggestions := make([]string, 0, len(providerSchema.DataSources))
+				for name := range providerSchema.DataSources {
+					suggestions = append(suggestions, name)
+				}
+				if suggestion = didyoumean.NameSuggestion(n.Config.Type, suggestions); suggestion != "" {
+					suggestion = fmt.Sprintf(" Did you mean %q?", suggestion)
+				}
+			}
+
 			diags = diags.Append(&hcl.Diagnostic{
 				Severity: hcl.DiagError,
 				Summary:  "Invalid data source",
-				Detail:   fmt.Sprintf("The provider %s does not support data source %q.", n.Config.ProviderConfigAddr(), n.Config.Type),
+				Detail:   fmt.Sprintf("The provider %s does not support data source %q.%s", n.Provider().ForDisplay(), n.Config.Type, suggestion),
 				Subject:  &n.Config.TypeRange,
 			})
 			return diags