Better identifiers compilation

Adding double quotes only when required
vfrz · Aug 8, 2023 · c10222e · c10222e
1 parent e1605f1
commit c10222e
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Showing 6 changed files with 69 additions and 14 deletions.
diff --git a/Sources/DotNetGraph.Tests/Core/DotEdgeTests.cs b/Sources/DotNetGraph.Tests/Core/DotEdgeTests.cs
@@ -24,7 +24,7 @@ public async Task CompileEmptyEdge()
         await edge.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"A\" -- \"B\"\n");
+        result.Should().Be("A -- B\n");
     }
 
     [TestMethod]
@@ -42,7 +42,7 @@ public async Task CompileEmptyDirectedEdge()
         await edge.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"A\" -> \"B\"\n");
+        result.Should().Be("A -> B\n");
     }
 
     [TestMethod]
@@ -96,6 +96,6 @@ public async Task CompileWithAttributes()
         await edge.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"A\" -> \"B\" [\n\t\"label\"=\"Test\"\n\t\"style\"=\"bold\"\n]\n");
+        result.Should().Be("A -> B [\n\t\"label\"=\"Test\"\n\t\"style\"=\"bold\"\n]\n");
     }
 }
diff --git a/Sources/DotNetGraph.Tests/Core/DotGraphTests.cs b/Sources/DotNetGraph.Tests/Core/DotGraphTests.cs
@@ -22,7 +22,7 @@ public async Task CompileEmptyGraph()
         await graph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("graph \"Test\" {\n}\n");
+        result.Should().Be("graph Test {\n}\n");
     }
 
     [TestMethod]
@@ -37,7 +37,7 @@ public async Task CompileEmptyStrictGraph()
         await graph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("strict graph \"Test\" {\n}\n");
+        result.Should().Be("strict graph Test {\n}\n");
     }
 
     [TestMethod]
@@ -52,7 +52,7 @@ public async Task CompileEmptyDirectedGraph()
         await graph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("digraph \"Test\" {\n}\n");
+        result.Should().Be("digraph Test {\n}\n");
     }
 
     [TestMethod]
@@ -68,7 +68,7 @@ public async Task CompileEmptyDirectedGraphWithRankDir()
         await graph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("digraph \"Test\" {\n\t\"rankdir\"=\"RL\"\n}\n");
+        result.Should().Be("digraph Test {\n\t\"rankdir\"=\"RL\"\n}\n");
     }
 
     [TestMethod]
@@ -87,6 +87,6 @@ public async Task CompileDirectedGraphWithOneNode()
         await graph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("digraph \"Test\" {\n\t\"TestNode\"\n}\n");
+        result.Should().Be("digraph Test {\n\tTestNode\n}\n");
     }
 }
diff --git a/Sources/DotNetGraph.Tests/Core/DotIdentifierTests.cs b/Sources/DotNetGraph.Tests/Core/DotIdentifierTests.cs
@@ -20,7 +20,39 @@ public async Task Compile()
         await identifier.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"Test\"");
+        result.Should().Be("Test");
+    }
+
+    [TestMethod]
+    public async Task CompileWithQuotes()
+    {
+        var identifier = new DotIdentifier("Hello, world!");
+
+        await using var writer = new StringWriter();
+        var context = new CompilationContext(writer, new CompilationOptions());
+        await identifier.CompileAsync(context);
+
+        var result = writer.GetStringBuilder().ToString();
+        result.Should().Be("\"Hello, world!\"");
+    }
+
+    [DataTestMethod]
+    [DataRow("graph")]
+    [DataRow("digraph")]
+    [DataRow("subgraph")]
+    [DataRow("strict")]
+    [DataRow("node")]
+    [DataRow("edge")]
+    public async Task CompileWithQuotesReservedWords(string identifierValue)
+    {
+        var identifier = new DotIdentifier(identifierValue);
+
+        await using var writer = new StringWriter();
+        var context = new CompilationContext(writer, new CompilationOptions());
+        await identifier.CompileAsync(context);
+
+        var result = writer.GetStringBuilder().ToString();
+        result.Should().Be($"\"{identifierValue}\"");
     }
 
     [TestMethod]

diff --git a/Sources/DotNetGraph.Tests/Core/DotNodeTests.cs b/Sources/DotNetGraph.Tests/Core/DotNodeTests.cs
@@ -23,7 +23,7 @@ public async Task CompileEmptyNode()
         await node.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"Test\"\n");
+        result.Should().Be("Test\n");
     }
 
     [TestMethod]
@@ -38,6 +38,6 @@ public async Task CompileNodeWithColor()
         await node.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("\"Test\" [\n\t\"color\"=\"#FF0000\"\n]\n");
+        result.Should().Be("Test [\n\t\"color\"=\"#FF0000\"\n]\n");
     }
 }
diff --git a/Sources/DotNetGraph.Tests/Core/DotSubgraphTests.cs b/Sources/DotNetGraph.Tests/Core/DotSubgraphTests.cs
@@ -22,6 +22,6 @@ public async Task CompileEmptySubgraph()
         await subgraph.CompileAsync(context);
 
         var result = writer.GetStringBuilder().ToString();
-        result.Should().Be("subgraph \"Test\" {\n}\n");
+        result.Should().Be("subgraph Test {\n}\n");
     }
 }
diff --git a/Sources/DotNetGraph/Core/DotIdentifier.cs b/Sources/DotNetGraph/Core/DotIdentifier.cs
@@ -1,3 +1,5 @@
+using System.Linq;
+using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using DotNetGraph.Compilation;
 using DotNetGraph.Extensions;
@@ -6,6 +8,19 @@ namespace DotNetGraph.Core
 {
     public class DotIdentifier : IDotElement
     {
+        private static readonly Regex NoQuotesRequiredRegex
+            = new Regex("^([a-zA-Z\\200-\\377_][a-zA-Z\\200-\\3770-9_]*|[-]?(.[0-9]+|[0-9]+(.[0-9]+)?))$");
+
+        private static readonly string[] ReservedWords =
+        {
+            "graph",
+            "digraph",
+            "subgraph",
+            "strict",
+            "node",
+            "edge"
+        };
+
         public string Value { get; set; }
 
         public bool IsHtml { get; set; } = false;
@@ -23,9 +38,17 @@ public async Task CompileAsync(CompilationContext context)
                 await context.TextWriter.WriteAsync($"<{Value}>");
                 return;
             }
-            
+
             var value = context.Options.AutomaticEscapedCharactersFormat ? Value.FormatGraphvizEscapedCharacters() : Value;
-            await context.TextWriter.WriteAsync($"\"{value}\"");
+            if (RequiresDoubleQuotes(value))
+                await context.TextWriter.WriteAsync($"\"{value}\"");
+            else
+                await context.TextWriter.WriteAsync($"{value}");
+        }
+
+        private static bool RequiresDoubleQuotes(string value)
+        {
+            return ReservedWords.Contains(value) || !NoQuotesRequiredRegex.IsMatch(value);
         }
     }
 }