decoder: Implement hover for Object

decoder/expr_object.go

@@ -17,11 +17,6 @@ type Object struct {
 	pathCtx *PathContext
 }
 
-func (obj Object) HoverAtPos(ctx context.Context, pos hcl.Pos) *lang.HoverData {
-	// TODO
-	return nil
-}
-
 func (obj Object) SemanticTokens(ctx context.Context) []lang.SemanticToken {
 	// TODO
 	return nil

decoder/expr_object_hover.go

@@ -0,0 +1,72 @@
+package decoder
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func (obj Object) HoverAtPos(ctx context.Context, pos hcl.Pos) *lang.HoverData {
+	eType, ok := obj.expr.(*hclsyntax.ObjectConsExpr)
+	if !ok {
+		return nil
+	}
+
+	for _, item := range eType.Items {
+		attrName, _, ok := getRawObjectAttributeName(item.KeyExpr)
+		if !ok {
+			continue
+		}
+
+		aSchema, ok := obj.cons.Attributes[attrName]
+		if !ok {
+			// unknown attribute
+			return nil
+		}
+
+		if item.KeyExpr.Range().ContainsPos(pos) {
+			itemRng := hcl.RangeBetween(item.KeyExpr.Range(), item.ValueExpr.Range())
+			content := hoverContentForAttribute(attrName, aSchema)
+
+			return &lang.HoverData{
+				Content: content,
+				Range:   itemRng,
+			}
+		}
+
+		if item.ValueExpr.Range().ContainsPos(pos) {
+			expr := newExpression(obj.pathCtx, item.ValueExpr, aSchema.Constraint)
+			return expr.HoverAtPos(ctx, pos)
+		}
+	}
+
+	content := ""
+	hoverData := obj.cons.EmptyHoverData(1)
+	if hoverData != nil {
+		content = hoverData.Content.Value
+	}
+	content += fmt.Sprintf("_%s_", obj.cons.FriendlyName())
+	if obj.cons.Description.Value != "" {
+		content += "\n\n" + obj.cons.Description.Value
+	}
+
+	return &lang.HoverData{
+		Content: lang.Markdown(content),
+		Range:   eType.Range(),
+	}
+}
+
+func hoverContentForAttribute(name string, aSchema *schema.AttributeSchema) lang.MarkupContent {
+	value := fmt.Sprintf("**%s** _%s_", name, detailForAttribute(aSchema))
+	if aSchema.Description.Value != "" {
+		value += fmt.Sprintf("\n\n%s", aSchema.Description.Value)
+	}
+	return lang.MarkupContent{
+		Kind:  lang.MarkdownKind,
+		Value: value,
+	}
+}