Added a bit more test coverage for subreads.

Schema Tests/binary/reader/SubreadLocalSpaceTests.cs

@@ -0,0 +1,166 @@
+using NUnit.Framework;
+
+namespace schema.binary;
+
+internal class SubreadLocalSpaceTests {
+  [Test]
+  public void TestSubreadWithoutReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    br.Subread(
+        50,
+        sbr => {
+          Assert.AreEqual(3, sbr.Position);
+          Assert.AreEqual(53, sbr.Length);
+
+          sbr.Position = 4;
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(53, sbr.Length);
+        });
+
+    Assert.AreEqual(53, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+
+  [Test]
+  public void TestSubreadWithReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    var returnValue = br.Subread(
+        50,
+        sbr => {
+          Assert.AreEqual(3, sbr.Position);
+          Assert.AreEqual(53, sbr.Length);
+
+          sbr.Position = 4;
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(53, sbr.Length);
+
+          return 123;
+        });
+    Assert.AreEqual(123, returnValue);
+
+    Assert.AreEqual(53, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+
+  [Test]
+  public void TestSubreadAtWithoutLengthWithoutReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    br.SubreadAt(
+        4,
+        sbr => {
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(98, sbr.Length);
+        });
+
+    Assert.AreEqual(3, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+
+  [Test]
+  public void TestSubreadAtWithLengthWithoutReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    br.SubreadAt(
+        4,
+        50,
+        sbr => {
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(54, sbr.Length);
+        });
+
+    Assert.AreEqual(3, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+
+  [Test]
+  public void TestSubreadAtWithoutLengthWithReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    var returnValue = br.SubreadAt(
+        4,
+        sbr => {
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(98, sbr.Length);
+          return 123;
+        });
+    Assert.AreEqual(123, returnValue);
+
+    Assert.AreEqual(3, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+
+  [Test]
+  public void TestSubreadAtWithLengthWithReturn() {
+    using var br = new SchemaBinaryReader(new byte[100]);
+
+    br.Position = 2;
+    br.PushLocalSpace();
+
+    Assert.AreEqual(0, br.Position);
+    Assert.AreEqual(98, br.Length);
+
+    br.Position = 3;
+    Assert.AreEqual(3, br.Position);
+
+    var returnValue = br.SubreadAt(
+        4,
+        50,
+        sbr => {
+          Assert.AreEqual(4, sbr.Position);
+          Assert.AreEqual(54, sbr.Length);
+          return 123;
+        });
+    Assert.AreEqual(123, returnValue);
+
+    Assert.AreEqual(3, br.Position);
+    Assert.AreEqual(98, br.Length);
+  }
+}

Schema/src/binary/reader/SchemaBinaryReader_Subread.cs

@@ -9,15 +9,7 @@ namespace schema.binary;
 public partial class SchemaBinaryReader {
   public void Subread(int len, Action<IBinaryReader> subread) {
     var baseOffset = this.Position;
-    var substream = new RangedReadableSubstream(this.BaseStream_,
-                                                baseOffset,
-                                                len);
-    using var sbr = new SchemaBinaryReader(substream, this.Endianness) {
-        AssertAlreadyAtOffset = this.AssertAlreadyAtOffset,
-    };
-    sbr.positionManagerImpl_ = new StreamPositionManager(substream);
-    subread(sbr);
-
+    this.SubreadAt(baseOffset, len, subread);
     this.Position = baseOffset + len;
   }