remove EvalReadDataApply

EvalReadDataApply was all dead code, as it was only using during delete
and simply set the state to nil.

terraform/eval_read_data.go

@@ -385,114 +385,3 @@ func (n *EvalReadData) Eval(ctx EvalContext) (interface{}, error) {
 
 	return nil, diags.ErrWithWarnings()
 }
-
-// EvalReadDataApply is an EvalNode implementation that executes a data
-// resource's ReadDataApply method to read data from the data source.
-type EvalReadDataApply struct {
-	Addr           addrs.ResourceInstance
-	Provider       *providers.Interface
-	ProviderAddr   addrs.AbsProviderConfig
-	ProviderMeta   *configs.ProviderMeta
-	ProviderSchema **ProviderSchema
-	Output         **states.ResourceInstanceObject
-	Config         *configs.Resource
-	Change         **plans.ResourceInstanceChange
-}
-
-func (n *EvalReadDataApply) Eval(ctx EvalContext) (interface{}, error) {
-	provider := *n.Provider
-	change := *n.Change
-	providerSchema := *n.ProviderSchema
-	absAddr := n.Addr.Absolute(ctx.Path())
-
-	var diags tfdiags.Diagnostics
-
-	// If the diff is for *destroying* this resource then we'll
-	// just drop its state and move on, since data resources don't
-	// support an actual "destroy" action.
-	if change != nil && change.Action == plans.Delete {
-		if n.Output != nil {
-			*n.Output = nil
-		}
-		return nil, nil
-	}
-
-	metaConfigVal := cty.NullVal(cty.DynamicPseudoType)
-	if n.ProviderMeta != nil {
-		// if the provider doesn't support this feature, throw an error
-		if (*n.ProviderSchema).ProviderMeta == nil {
-			diags = diags.Append(&hcl.Diagnostic{
-				Severity: hcl.DiagError,
-				Summary:  fmt.Sprintf("Provider %s doesn't support provider_meta", n.ProviderAddr.Provider.String()),
-				Detail:   fmt.Sprintf("The resource %s belongs to a provider that doesn't support provider_meta blocks", n.Addr),
-				Subject:  &n.ProviderMeta.ProviderRange,
-			})
-		} else {
-			var configDiags tfdiags.Diagnostics
-			metaConfigVal, _, configDiags = ctx.EvaluateBlock(n.ProviderMeta.Config, (*n.ProviderSchema).ProviderMeta, nil, EvalDataForNoInstanceKey)
-			diags = diags.Append(configDiags)
-			if configDiags.HasErrors() {
-				return nil, diags.Err()
-			}
-		}
-	}
-
-	// For the purpose of external hooks we present a data apply as a
-	// "Refresh" rather than an "Apply" because creating a data source
-	// is presented to users/callers as a "read" operation.
-	err := ctx.Hook(func(h Hook) (HookAction, error) {
-		// We don't have a state yet, so we'll just give the hook an
-		// empty one to work with.
-		return h.PreRefresh(absAddr, states.CurrentGen, cty.NullVal(cty.DynamicPseudoType))
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	resp := provider.ReadDataSource(providers.ReadDataSourceRequest{
-		TypeName:     n.Addr.Resource.Type,
-		Config:       change.After,
-		ProviderMeta: metaConfigVal,
-	})
-	diags = diags.Append(resp.Diagnostics.InConfigBody(n.Config.Config))
-	if diags.HasErrors() {
-		return nil, diags.Err()
-	}
-
-	schema, _ := providerSchema.SchemaForResourceAddr(n.Addr.ContainingResource())
-	if schema == nil {
-		// Should be caught during validation, so we don't bother with a pretty error here
-		return nil, fmt.Errorf("provider does not support data source %q", n.Addr.Resource.Type)
-	}
-
-	newVal := resp.State
-	for _, err := range newVal.Type().TestConformance(schema.ImpliedType()) {
-		diags = diags.Append(tfdiags.Sourceless(
-			tfdiags.Error,
-			"Provider produced invalid object",
-			fmt.Sprintf(
-				"Provider %q planned an invalid value for %s. The result could not be saved.\n\nThis is a bug in the provider, which should be reported in the provider's own issue tracker.",
-				n.ProviderAddr.Provider.String(), tfdiags.FormatErrorPrefixed(err, absAddr.String()),
-			),
-		))
-	}
-	if diags.HasErrors() {
-		return nil, diags.Err()
-	}
-
-	err = ctx.Hook(func(h Hook) (HookAction, error) {
-		return h.PostRefresh(absAddr, states.CurrentGen, change.Before, newVal)
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	if n.Output != nil {
-		*n.Output = &states.ResourceInstanceObject{
-			Value:  newVal,
-			Status: states.ObjectReady,
-		}
-	}
-
-	return nil, diags.ErrWithWarnings()
-}

terraform/node_resource_destroy.go

@@ -237,19 +237,14 @@ func (n *NodeDestroyResourceInstance) EvalTree() EvalNode {
 				// Make sure we handle data sources properly.
 				&EvalIf{
 					If: func(ctx EvalContext) (bool, error) {
-						return addr.Resource.Resource.Mode == addrs.DataResourceMode, nil
+						if addr.Resource.Resource.Mode == addrs.DataResourceMode {
+							// deleting a data source is simply removing the state
+							state = nil
+						}
+						return addr.Resource.Resource.Mode == addrs.ManagedResourceMode, nil
 					},
 
-					Then: &EvalReadDataApply{
+					Then: &EvalApply{
-						Addr:           addr.Resource,
-						Config:         n.Config,
-						Change:         &changeApply,
-						Provider:       &provider,
-						ProviderAddr:   n.ResolvedProvider,
-						ProviderSchema: &providerSchema,
-						Output:         &state,
-					},
-					Else: &EvalApply{
 						Addr:           addr.Resource,
 						Config:         nil, // No configuration because we are destroying
 						State:          &state,