decoder: validate required attributes more selectively

internal/decoder/validations/missing_required_attribute.go

@@ -0,0 +1,70 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package validations
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/hcl-lang/schemacontext"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+type MissingRequiredAttribute struct{}
+
+func (mra MissingRequiredAttribute) Visit(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema) (context.Context, hcl.Diagnostics) {
+	var diags hcl.Diagnostics
+	if HasUnknownRequiredAttributes(ctx) {
+		return ctx, diags
+	}
+
+	switch nodeType := node.(type) {
+	case *hclsyntax.Block:
+		// Providers are excluded from the validation for the time being
+		// due to complexity around required attributes with dynamic defaults
+		// See https://github.com/hashicorp/vscode-terraform/issues/1616
+		nestingLvl, nestingOk := schemacontext.BlockNestingLevel(ctx)
+		if nodeType.Type == "provider" && (nestingOk && nestingLvl == 0) {
+			ctx = WithUnknownRequiredAttributes(ctx)
+		}
+	case *hclsyntax.Body:
+		if nodeSchema == nil {
+			return ctx, diags
+		}
+
+		bodySchema := nodeSchema.(*schema.BodySchema)
+		if bodySchema.Attributes == nil {
+			return ctx, diags
+		}
+
+		for name, attr := range bodySchema.Attributes {
+			if attr.IsRequired {
+				_, ok := nodeType.Attributes[name]
+				if !ok {
+					diags = append(diags, &hcl.Diagnostic{
+						Severity: hcl.DiagError,
+						Summary:  fmt.Sprintf("Required attribute %q not specified", name),
+						Detail:   fmt.Sprintf("An attribute named %q is required here", name),
+						Subject:  nodeType.SrcRange.Ptr(),
+					})
+				}
+			}
+		}
+	}
+
+	return ctx, diags
+}
+
+type unknownRequiredAttrsCtxKey struct{}
+
+func HasUnknownRequiredAttributes(ctx context.Context) bool {
+	_, ok := ctx.Value(unknownRequiredAttrsCtxKey{}).(bool)
+	return ok
+}
+
+func WithUnknownRequiredAttributes(ctx context.Context) context.Context {
+	return context.WithValue(ctx, unknownRequiredAttrsCtxKey{}, true)
+}

internal/decoder/validators.go

@@ -5,6 +5,7 @@ package decoder
 
 import (
 	"github.com/hashicorp/hcl-lang/validator"
+	"github.com/hashicorp/terraform-ls/internal/decoder/validations"
 )
 
 var moduleValidators = []validator.Validator{
@@ -13,7 +14,7 @@ var moduleValidators = []validator.Validator{
 	validator.DeprecatedBlock{},
 	validator.MaxBlocks{},
 	validator.MinBlocks{},
-	validator.MissingRequiredAttribute{},
+	validations.MissingRequiredAttribute{},
 	validator.UnexpectedAttribute{},
 	validator.UnexpectedBlock{},
 }