fix: handle nil expr for hover

decoder/hover.go

@@ -80,7 +80,7 @@ func (d *PathDecoder) hoverAtPos(ctx context.Context, body *hclsyntax.Body, body
 				}, nil
 			}
 
-			if attr.Expr.Range().ContainsPos(pos) {
+			if attr.Expr != nil && attr.Expr.Range().ContainsPos(pos) {
 				return d.newExpression(attr.Expr, aSchema.Constraint).HoverAtPos(ctx, pos), nil
 			}
 		}

decoder/hover_test.go

@@ -661,6 +661,35 @@ func TestDecoder_HoverAtPos_basic(t *testing.T) {
 	}
 }
 
+func TestDecoder_HoverAtPos_nil_expr(t *testing.T) {
+	// provider:: is not a traversal expression, so hcl will return a nil expression which needs to be
+	// handled gracefully
+	f, _ := hclsyntax.ParseConfig([]byte(`attr = provider::`), "test.tf", hcl.InitialPos)
+
+	d := testPathDecoder(t, &PathContext{
+		Schema: &schema.BodySchema{
+			Attributes: map[string]*schema.AttributeSchema{
+				"attr": {Constraint: schema.AnyExpression{OfType: cty.DynamicPseudoType}},
+			},
+		},
+		Files: map[string]*hcl.File{
+			"test.tf": f,
+		},
+	})
+
+	ctx := context.Background()
+	_, err := d.HoverAtPos(ctx, "test.tf", hcl.Pos{Line: 1, Column: 16, Byte: 15})
+
+	if err == nil {
+		t.Fatal("expected error")
+	}
+
+	positionalErr := &PositionalError{}
+	if !errors.As(err, &positionalErr) {
+		t.Fatal("expected PositionalError for invalid expression")
+	}
+}
+
 func TestDecoder_HoverAtPos_URL(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
 		{Name: "type", IsDepKey: true},