fix(rslint_parser): Fix arrow parsing (rome#2284)

Allows parsing of single parameter async function where the parameter is named `async`
F3n67u · Mar 22, 2022 · 001bdaa · 001bdaa
1 parent 1b303cf
commit 001bdaa
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Showing 3 changed files with 78 additions and 5 deletions.
diff --git a/crates/rslint_parser/src/syntax/function.rs b/crates/rslint_parser/src/syntax/function.rs
@@ -750,12 +750,19 @@ fn parse_arrow_function_with_single_parameter(p: &mut Parser) -> ParsedSyntax {
 }
 
 fn is_arrow_function_with_single_parameter(p: &mut Parser) -> bool {
-    if p.at(T![async]) && !p.has_nth_preceding_line_break(1) {
-        is_nth_at_identifier_binding(p, 1)
-            && p.nth_at(2, T![=>])
+    // a => ...
+    if p.nth_at(1, T![=>]) {
+        // test single_parameter_arrow_function_with_parameter_named_async
+        // let id = async => async;
+        is_at_identifier_binding(p) && !p.has_nth_preceding_line_break(1)
+    }
+    // async ident => ...
+    else {
+        p.at(T![async])
+            && !p.has_nth_preceding_line_break(1)
+            && is_nth_at_identifier_binding(p, 1)
             && !p.has_nth_preceding_line_break(2)
-    } else {
-        is_at_identifier_binding(p) && p.nth_at(1, T![=>]) && !p.has_nth_preceding_line_break(1)
+            && p.nth_at(2, T![=>])
     }
 }
 

diff --git a/..._parser/test_data/inline/ok/single_parameter_arrow_function_with_parameter_named_async.js b/..._parser/test_data/inline/ok/single_parameter_arrow_function_with_parameter_named_async.js
@@ -0,0 +1 @@
+let id = async => async;
diff --git a/...arser/test_data/inline/ok/single_parameter_arrow_function_with_parameter_named_async.rast b/...arser/test_data/inline/ok/single_parameter_arrow_function_with_parameter_named_async.rast
@@ -0,0 +1,65 @@
+JsModule {
+    interpreter_token: missing (optional),
+    directives: JsDirectiveList [],
+    items: JsModuleItemList [
+        JsVariableStatement {
+            declaration: JsVariableDeclaration {
+                kind: [email protected] "let" [] [Whitespace(" ")],
+                declarators: JsVariableDeclaratorList [
+                    JsVariableDeclarator {
+                        id: JsIdentifierBinding {
+                            name_token: [email protected] "id" [] [Whitespace(" ")],
+                        },
+                        variable_annotation: missing (optional),
+                        initializer: JsInitializerClause {
+                            eq_token: [email protected] "=" [] [Whitespace(" ")],
+                            expression: JsArrowFunctionExpression {
+                                async_token: missing (optional),
+                                type_parameters: missing (optional),
+                                parameters: JsIdentifierBinding {
+                                    name_token: [email protected] "async" [] [Whitespace(" ")],
+                                },
+                                return_type_annotation: missing (optional),
+                                fat_arrow_token: [email protected] "=>" [] [Whitespace(" ")],
+                                body: JsIdentifierExpression {
+                                    name: JsReferenceIdentifier {
+                                        value_token: [email protected] "async" [] [],
+                                    },
+                                },
+                            },
+                        },
+                    },
+                ],
+            },
+            semicolon_token: [email protected] ";" [] [],
+        },
+    ],
+    eof_token: [email protected] "" [Newline("\n")] [],
+}
+
+0: [email protected]
+  0: (empty)
+  1: [email protected]
+  2: [email protected]
+    0: [email protected]
+      0: [email protected]
+        0: [email protected] "let" [] [Whitespace(" ")]
+        1: [email protected]
+          0: [email protected]
+            0: [email protected]
+              0: [email protected] "id" [] [Whitespace(" ")]
+            1: (empty)
+            2: [email protected]
+              0: [email protected] "=" [] [Whitespace(" ")]
+              1: [email protected]
+                0: (empty)
+                1: (empty)
+                2: [email protected]
+                  0: [email protected] "async" [] [Whitespace(" ")]
+                3: (empty)
+                4: [email protected] "=>" [] [Whitespace(" ")]
+                5: [email protected]
+                  0: [email protected]
+                    0: [email protected] "async" [] []
+      1: [email protected] ";" [] []
+  3: [email protected] "" [Newline("\n")] []