diff --git a/decoder/internal/walker/walker_test.go b/decoder/internal/walker/walker_test.go
new file mode 100644
index 00000000..ace51d20
--- /dev/null
+++ b/decoder/internal/walker/walker_test.go
@@ -0,0 +1,160 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package walker
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/hcl-lang/schemacontext"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func TestWalk_basic(t *testing.T) {
+	ctx := context.Background()
+	src := []byte(`
+first {
+  nested1 {}
+  nested2 {}
+}
+second {
+  foo = "bar"
+}
+`)
+	file, diags := hclsyntax.ParseConfig(src, "test.hcl", hcl.InitialPos)
+	if len(diags) > 0 {
+		t.Fatalf("unexpected parser diagnostics: %s", diags)
+	}
+
+	rootSchema := schema.NewBodySchema()
+	nodeCount := 0
+	tw := NewTestWalker(func(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema) (context.Context, hcl.Diagnostics) {
+		nodeCount++
+		return ctx, nil
+	})
+	diags = Walk(ctx, file.Body.(*hclsyntax.Body), rootSchema, tw)
+	if len(diags) > 0 {
+		t.Fatalf("unexpected diagnostics: %s", diags)
+	}
+	// root body + first(block+body) + nested1(block+body) + nested2(block+body) + second(block+body) + foo
+	expectedNodeCount := 10
+	if nodeCount != expectedNodeCount {
+		t.Fatalf("unexpected node count: %d, expected: %d", nodeCount, expectedNodeCount)
+	}
+}
+
+func TestWalk_nestingLevel(t *testing.T) {
+	ctx := context.Background()
+	src := []byte(`
+first {
+  nested1 {}
+  nested2 {}
+}
+rootattr = "foo"
+second {
+  foo = "bar"
+}
+`)
+	file, pDiags := hclsyntax.ParseConfig(src, "test.hcl", hcl.InitialPos)
+	if len(pDiags) > 0 {
+		t.Fatalf("unexpected parser diagnostics: %s", pDiags)
+	}
+
+	rootSchema := schema.NewBodySchema()
+
+	firstBlockFound := false
+	nestedBlockFound := false
+	rootAttrFound := false
+	nestedAttrFound := false
+
+	tw := NewTestWalker(func(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema) (context.Context, hcl.Diagnostics) {
+		var diags hcl.Diagnostics
+
+		nestingLvl, ok := schemacontext.BlockNestingLevel(ctx)
+		if !ok {
+			diags = diags.Append(&hcl.Diagnostic{
+				Severity: hcl.DiagError,
+				Summary:  "nesting level not available",
+			})
+		}
+
+		if block, ok := node.(*hclsyntax.Block); ok && block.Type == "first" {
+			firstBlockFound = true
+			if nestingLvl != 0 {
+				diags = diags.Append(&hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  fmt.Sprintf("%q: unexpected nesting level %d, expected 0", "first", nestingLvl),
+				})
+			}
+		}
+		if block, ok := node.(*hclsyntax.Block); ok && block.Type == "nested2" {
+			nestedBlockFound = true
+			if nestingLvl != 1 {
+				diags = diags.Append(&hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  fmt.Sprintf("%q: unexpected nesting level %d, expected 1", "nested2", nestingLvl),
+				})
+			}
+		}
+
+		if attr, ok := node.(*hclsyntax.Attribute); ok && attr.Name == "rootattr" {
+			rootAttrFound = true
+			if nestingLvl != 0 {
+				diags = diags.Append(&hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  fmt.Sprintf("%q: unexpected nesting level %d, expected 0", "rootattr", nestingLvl),
+				})
+			}
+		}
+
+		if attr, ok := node.(*hclsyntax.Attribute); ok && attr.Name == "foo" {
+			nestedAttrFound = true
+			if nestingLvl != 1 {
+				diags = diags.Append(&hcl.Diagnostic{
+					Severity: hcl.DiagError,
+					Summary:  fmt.Sprintf("%q: unexpected nesting level %d, expected 1", "foo", nestingLvl),
+				})
+			}
+		}
+
+		return ctx, diags
+	})
+
+	diags := Walk(ctx, file.Body.(*hclsyntax.Body), rootSchema, tw)
+	if len(diags) > 0 {
+		t.Fatalf("unexpected diagnostics: %s", diags)
+	}
+
+	if !firstBlockFound {
+		t.Error("expected first block to be found")
+	}
+	if !nestedBlockFound {
+		t.Error("expected nested block to be found")
+	}
+	if !rootAttrFound {
+		t.Error("expected root attribute to be found")
+	}
+	if !nestedAttrFound {
+		t.Error("expected nested attribute to be found")
+	}
+}
+
+func NewTestWalker(visitFunc visitFunc) Walker {
+	return testWalker{
+		visitFunc: visitFunc,
+	}
+}
+
+type visitFunc func(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema) (context.Context, hcl.Diagnostics)
+
+type testWalker struct {
+	visitFunc visitFunc
+}
+
+func (tw testWalker) Visit(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema) (context.Context, hcl.Diagnostics) {
+	return tw.visitFunc(ctx, node, nodeSchema)
+}