Support multiple sheets of the same type

.github/workflows/test.yml

@@ -21,10 +21,6 @@ jobs:
     steps:
       - name: Checkout source
         uses: actions/checkout@v2
-      - name: Use .NET Core 2.2 SDK
-        uses: actions/setup-dotnet@v1
-        with:
-          dotnet-version: '2.2.x'
       - name: Use .NET Core 3.1 LTS SDK
         uses: actions/setup-dotnet@v1
         with:

src/Shane32.ExcelLinq.Tests/Builders/Sheet.cs

@@ -84,11 +84,11 @@ public void CantAddDuplicateSheetName()
         }
 
         [TestMethod]
-        public void CantAddDuplicateSheetClass()
+        public void CanAddDuplicateSheetClass()
         {
             var builder = new ExcelModelBuilder();
             builder.Sheet<Class1>("Sheet1");
-            Assert.ThrowsException<InvalidOperationException>(() => builder.Sheet<Class1>("Sheet2"));
+            builder.Sheet<Class1>("Sheet2");
         }
 
         [TestMethod]

src/Shane32.ExcelLinq.Tests/General/EndToEnd.cs

@@ -170,5 +170,49 @@ public void ReadDynamicallyGeneratedFile()
             Assert.AreEqual(true, sheet1Data[1].BooleanColumn);
             mock.Verify();
         }
+
+        [TestMethod]
+        public void ReadWriteFileWithSimilarSheets()
+        {
+            var file = new TestFileContextSimilarSheets();
+            Assert.AreEqual(file.GetSheet<Class1>(), file.GetSheet<Class1>("Sheet1"));
+            file.GetSheet<Class1>("Sheet1").Add(new Class1 { StringColumn = "a", IntColumn = 1 });
+            file.GetSheet<Class1>("Sheet1").Add(new Class1 { StringColumn = "b", IntColumn = 2 });
+            file.GetSheet<Class1>("Sheet2").Add(new Class1 { StringColumn = "c", IntColumn = 3 });
+            file.GetSheet<Class1>("Sheet3").Add(new Class1 { StringColumn = "d", IntColumn = 4 });
+            var stream = file.SerializeToStream();
+            file = new TestFileContextSimilarSheets(stream);
+            Assert.AreEqual(file.GetSheet<Class1>(), file.GetSheet<Class1>("Sheet1"));
+            var sheet1 = file.GetSheet<Class1>("Sheet1");
+            Assert.AreEqual(sheet1.Count, 2);
+            Assert.AreEqual(sheet1[0].StringColumn, "a");
+            Assert.AreEqual(sheet1[0].IntColumn, 0);
+            Assert.AreEqual(sheet1[1].StringColumn, "b");
+            Assert.AreEqual(sheet1[1].IntColumn, 0);
+            var sheet2 = file.GetSheet<Class1>("Sheet2");
+            Assert.AreEqual(sheet2.Count, 1);
+            Assert.AreEqual(sheet2[0].StringColumn, "c");
+            Assert.AreEqual(sheet2[0].IntColumn, 0);
+            var sheet3 = file.GetSheet<Class1>("Sheet3");
+            Assert.AreEqual(sheet3.Count, 1);
+            Assert.AreEqual(sheet3[0].StringColumn, "d");
+            Assert.AreEqual(sheet3[0].IntColumn, 4);
+        }
+
+        private class TestFileContextSimilarSheets : ExcelContext
+        {
+            public TestFileContextSimilarSheets() : base() { }
+            public TestFileContextSimilarSheets(Stream stream) : base(stream) { }
+            protected override void OnModelCreating(ExcelModelBuilder modelBuilder)
+            {
+                var sheet1 = modelBuilder.Sheet<Class1>("Sheet1");
+                sheet1.Column(x => x.StringColumn);
+                var sheet2 = modelBuilder.Sheet<Class1>("Sheet2");
+                sheet2.Column(x => x.StringColumn);
+                var sheet3 = modelBuilder.Sheet<Class1>("Sheet3");
+                sheet3.Column(x => x.StringColumn);
+                sheet3.Column(x => x.IntColumn);
+            }
+        }
     }
 }

src/Shane32.ExcelLinq/Builders/SheetModelBuilder.cs

@@ -25,11 +25,10 @@ public SheetModelBuilder(ExcelModelBuilder excelModelBuilder, string name)
             _excelModelBuilder = excelModelBuilder ?? throw new ArgumentNullException(nameof(name));
             if (string.IsNullOrWhiteSpace(name)) throw new ArgumentNullException(nameof(name));
             _sheetName = name.Trim();
-            if (excelModelBuilder._typeDictionary.ContainsKey(typeof(T)))
-                throw new InvalidOperationException($"Type {typeof(T).Name} already exists in the database model");
             excelModelBuilder._sheetDictionary.Add(_sheetName.ToLower(), this);
             excelModelBuilder._sheets.Add(this);
-            excelModelBuilder._typeDictionary.Add(typeof(T), this);
+            if (!excelModelBuilder._typeDictionary.ContainsKey(typeof(T)))
+                excelModelBuilder._typeDictionary.Add(typeof(T), this);
         }
 
         public SheetModelBuilder<T> AlternateName(string name)

src/Shane32.ExcelLinq/ExcelContext.cs

@@ -32,7 +32,8 @@ protected ExcelContext()
                 _sheets.Add(CreateListForSheet(sheet.Type));
                 _sheetNameLookup.Add(sheet.Name, i);
                 foreach (var sheetName in sheet.AlternateNames) _sheetNameLookup.Add(sheetName, i);
-                _typeLookup.Add(sheet.Type, i);
+                if (!_typeLookup.ContainsKey(sheet.Type))
+                    _typeLookup.Add(sheet.Type, i);
             }
             _initialized = true;
         }
@@ -50,7 +51,8 @@ internal ExcelContext(IExcelModel model)
                 _sheets.Add(CreateListForSheet(sheet.Type));
                 _sheetNameLookup.Add(sheet.Name, i);
                 foreach (var sheetName in sheet.AlternateNames) _sheetNameLookup.Add(sheetName, i);
-                _typeLookup.Add(sheet.Type, i);
+                if (!_typeLookup.ContainsKey(sheet.Type))
+                    _typeLookup.Add(sheet.Type, i);
             }
             _initialized = true;
         }
@@ -479,6 +481,15 @@ public List<T> GetSheet<T>()
             return (List<T>)_sheets[_typeLookup[typeof(T)]];
         }
 
+        public List<T> GetSheet<T>(string name)
+        {
+            if (!_initialized)
+                throw new InvalidOperationException();
+            if (name == null)
+                throw new ArgumentNullException(nameof(name));
+            return (List<T>)_sheets[_sheetNameLookup[name]];
+        }
+
         public virtual ExcelPackage SerializeToExcelPackage()
         {
             var excelPackage = new ExcelPackage();