Merge pull request dotnet#70 from DustinCampbell/issue-69

Properly highlight throw expressions

Author: DustinCampbell

grammars/csharp.tmLanguage

@@ -371,6 +371,10 @@
             <key>include</key>
             <string>#nameof-expression</string>
           </dict>
+          <dict>
+            <key>include</key>
+            <string>#throw-expression</string>
+          </dict>
           <dict>
             <key>include</key>
             <string>#interpolated-string</string>
@@ -3904,6 +3908,28 @@
           </dict>
         </array>
       </dict>
+      <key>throw-expression</key>
+      <dict>
+        <key>begin</key>
+        <string>(?&lt;!\.)\b(throw)\b</string>
+        <key>beginCaptures</key>
+        <dict>
+          <key>1</key>
+          <dict>
+            <key>name</key>
+            <string>keyword.control.flow.throw.cs</string>
+          </dict>
+        </dict>
+        <key>end</key>
+        <string>(?=;)</string>
+        <key>patterns</key>
+        <array>
+          <dict>
+            <key>include</key>
+            <string>#expression</string>
+          </dict>
+        </array>
+      </dict>
       <key>interpolated-string</key>
       <dict>
         <key>name</key>

grammars/csharp.tmLanguage.cson

@@ -261,6 +261,9 @@ repository:
       {
         include: "#nameof-expression"
       }
+      {
+        include: "#throw-expression"
+      }
       {
         include: "#interpolated-string"
       }
@@ -2383,6 +2386,17 @@ repository:
         include: "#expression"
       }
     ]
+  "throw-expression":
+    begin: "(?<!\\.)\\b(throw)\\b"
+    beginCaptures:
+      "1":
+        name: "keyword.control.flow.throw.cs"
+    end: "(?=;)"
+    patterns: [
+      {
+        include: "#expression"
+      }
+    ]
   "interpolated-string":
     name: "string.quoted.double.cs"
     begin: "\\$\""

src/csharp.tmLanguage.yml

@@ -108,6 +108,7 @@ repository:
     - include: '#checked-unchecked-expression'
     - include: '#typeof-or-default-expression'
     - include: '#nameof-expression'
+    - include: '#throw-expression'
     - include: '#interpolated-string'
     - include: '#verbatim-interpolated-string'
     - include: '#this-or-base-expression'
@@ -1488,6 +1489,14 @@ repository:
     patterns:
     - include: '#expression'
 
+  throw-expression:
+    begin: (?<!\.)\b(throw)\b
+    beginCaptures:
+      '1': { name: keyword.control.flow.throw.cs }
+    end: (?=;)
+    patterns:
+    - include: '#expression'
+
   interpolated-string:
     name: string.quoted.double.cs
     begin: '\$"'

test/expressions.tests.ts

@@ -3027,7 +3027,54 @@ private static readonly Parser<Node> NodeParser =
                     Token.Punctuation.Semicolon
                 ]);
             });
+        });
+
+        describe("Throw expressions", () => {
+            it("throw expression in expression-bodied member (issue #69)", () => {
+                const input = Input.InClass(`public static void A(string str) => throw new Exception(str);`);
+                const tokens = tokenize(input);
 
+                tokens.should.deep.equal([
+                    Token.Keywords.Modifiers.Public,
+                    Token.Keywords.Modifiers.Static,
+                    Token.PrimitiveType.Void,
+                    Token.Identifiers.MethodName("A"),
+                    Token.Punctuation.OpenParen,
+                    Token.PrimitiveType.String,
+                    Token.Identifiers.ParameterName("str"),
+                    Token.Punctuation.CloseParen,
+                    Token.Operators.Arrow,
+                    Token.Keywords.Control.Throw,
+                    Token.Keywords.New,
+                    Token.Type("Exception"),
+                    Token.Punctuation.OpenParen,
+                    Token.Variables.ReadWrite("str"),
+                    Token.Punctuation.CloseParen,
+                    Token.Punctuation.Semicolon
+                ]);
+            });
+
+            it("throw expression in assignment", () => {
+                const input = Input.InMethod(`_field = field ?? throw new ArgumentNullException(nameof(field));`);
+                const tokens = tokenize(input);
+
+                tokens.should.deep.equal([
+                    Token.Variables.ReadWrite("_field"),
+                    Token.Operators.Assignment,
+                    Token.Variables.ReadWrite("field"),
+                    Token.Operators.NullCoalescing,
+                    Token.Keywords.Control.Throw,
+                    Token.Keywords.New,
+                    Token.Type("ArgumentNullException"),
+                    Token.Punctuation.OpenParen,
+                    Token.Keywords.NameOf,
+                    Token.Punctuation.OpenParen,
+                    Token.Variables.ReadWrite("field"),
+                    Token.Punctuation.CloseParen,
+                    Token.Punctuation.CloseParen,
+                    Token.Punctuation.Semicolon
+                ]);
+            });
         });
     });
 });