Support constant operators symbol detection

Signed-off-by: PoorlyDefinedBehaviour <brunotj2015@hotmail.com>

Author: PoorlyDefinedBehaviour

src/symbols/tlaSymbols.ts

@@ -306,7 +306,11 @@ export class TlaDocumentSymbolsProvider implements vscode.DocumentSymbolProvider
                 charIdx += COMMA_LEN;
                 continue;
             }
-            if (rest !== '' && !isCommentStart(rest)) {
+
+            // Given a constant operator like Foo(_, _, ...), match the parentheses and everything inside of it
+            const isConstantOperator = /^(\(((\s*_\s*,|\s*_\s*)\s*)+\))$/.test(rest);
+
+            if (rest !== '' && !isCommentStart(rest) &&!isConstantOperator) {
                 module.simpleListSymbolKind = undefined;
                 return false;
             }
@@ -317,7 +321,11 @@ export class TlaDocumentSymbolsProvider implements vscode.DocumentSymbolProvider
                 new vscode.Location(docUri, new vscode.Position(lineNum, charIdx))
             ));
             charIdx += name.length + spaces.length + COMMA_LEN;
-            if (rest !== '') {
+            if (isConstantOperator) {
+                // Skip '(...)' in constant operators e.g. Foo(_, _)
+                charIdx += rest.length;
+            }
+            if (rest !== '' && !isConstantOperator) {
                 module.simpleListSymbolKind = undefined;
                 break;      // There were no comma after the name
             }

tests/suite/symbols/tlaSymbols.test.ts

@@ -52,6 +52,84 @@ suite('TLA Symbols Provider Test Suite', () => {
         ]);
     });
 
+    test('Finds items in CONSTANT operators', () => {
+        const cases = [
+            {
+                input: [
+                    'CONSTANTS Baz(_)'
+                ],
+                expected: [
+                    symConst('Baz', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Baz( _ )'
+                ],
+                expected: [
+                    symConst('Baz', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Baz(_, _)'
+                ],
+                expected: [
+                    symConst('Baz', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Foo(_), Bar'
+                ],
+                expected: [
+                    symConst('Foo', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10))),
+                    symConst('Bar', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 18)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Bar, Foo(_)'
+                ],
+                expected: [
+                    symConst('Bar', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10))),
+                    symConst('Foo', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 18)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Foo(_, _), Bar'
+                ],
+                expected: [
+                    symConst('Foo', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10))),
+                    symConst('Bar', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 20)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Bar, Foo(_, _)'
+                ],
+                expected: [
+                    symConst('Bar', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10))),
+                    symConst('Foo', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 18)))
+                ]
+            },
+            {
+                input: [
+                    'CONSTANTS Bar, Foo(_, _, _), Baz'
+                ],
+                expected: [
+                    symConst('Bar', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 10))),
+                    symConst('Foo', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 18))),
+                    symConst('Baz', ROOT_CONTAINER_NAME, loc(doc.uri, pos(0, 29))),
+                ]
+            }
+        ];
+        for (const {input, expected} of cases) {
+            return assertSymbols(doc, input, expected);
+        }
+    });
+
     test('Finds items in VARIABLE', () => {
         return assertSymbols(doc, [
             'VARIABLE Foo, Bar'