When detecting arrow '<T extends' is not guaranteed to be type parameter of arrow as it could be type assertion with conditional type

Fixes #748

Author: sheetalkamat

TypeScript.YAML-tmLanguage

@@ -68,6 +68,7 @@ variables:
   typeArguments: '<\s*{{typeArgumentsStart}}({{typeArgumentsInnerExpressionPart}}|\<\s*{{typeArgumentsStart}}(({{typeArgumentsInnerExpressionPart}}|\<\s*{{typeArgumentsStart}}({{typeArgumentsInnerExpressionPart}})*(?<!=)\>))*(?<!=)\>)*(?<!=)>'
   functionCallLookup: \s*(\?\.\s*)?({{typeArguments}}\s*)?\(
   returnTypeOfArrow: \s*([^<>\(\)\{\}]|\<([^<>]|\<[^<>]+\>)+\>|\([^\(\)]+\)|\{[^\{\}]+\})+
+  typeparamertStartOfArrow: ''
   arrowLookup: |-
     # sure shot arrow functions even if => is on new line
     (
@@ -78,9 +79,7 @@ variables:
         ((\.\.\.\s*)?{{identifier}}\s*:)                                                                  # [(]param: | [(]...param:
       )
     ) |
-    (
-      [<]\s*{{identifier}}\s+extends\s*[^=>]                                                              # < typeparam extends
-    ) |
+    {{typeparamertStartOfArrow}}
     # arrow function possible to detect only with => on same line
     (
       {{typeParameters}}?                                                                                 # typeparameters

TypeScript.tmLanguage

@@ -634,9 +634,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -676,9 +674,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -796,9 +792,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -838,9 +832,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -1461,9 +1453,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -1503,9 +1493,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -1923,9 +1911,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -1965,9 +1951,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -2524,9 +2508,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -4356,9 +4338,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -4916,9 +4896,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -4958,9 +4936,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters
@@ -6277,9 +6253,7 @@
     ((\.\.\.\s*)?[_$[:alpha:]][_$[:alnum:]]*\s*:)                                                                  # [(]param: | [(]...param:
   )
 ) |
-(
-  [<]\s*[_$[:alpha:]][_$[:alnum:]]*\s+extends\s*[^=>]                                                              # < typeparam extends
-) |
+
 # arrow function possible to detect only with => on same line
 (
   (<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<]|\<\s*([_$[:alpha:]]|(\{([^\{\}]|(\{[^\{\}]*\}))*\})|(\(([^\(\)]|(\([^\(\)]*\)))*\))|(\[([^\[\]]|(\[[^\[\]]*\]))*\]))([^=<>]|=[^<])*\>)*\>)*>\s*)?                                                                                 # typeparameters

TypeScriptReact.YAML-tmLanguage

@@ -9,6 +9,11 @@ fileTypes: [tsx]
 uuid: 805375ec-d614-41f5-8993-5843fe63ea82
 
 variables:
+  # because tsx cannot have cast expression, we can say <T extends starts the type parameter of arrow
+  typeparamertStartOfArrow: |-
+    (
+      [<]\s*{{identifier}}\s+extends\s*[^=>]                                                              # < typeparam extends
+    ) |
   #possiblyMultilineArrowExpressionBeforeEndOfLine: ({{typeParameters}})?\(
   possiblyMultilineArrow: ((<\s*$)|([\(]\s*([\{\[]\s*)?$))  # during lookup treat ( followed by line end as arrow
   jsxTagOrAtrributeIdentifier: '[_$[:alpha:]][-_$[:alnum:].]*'

tests/baselines/Issue637.baseline.txt

@@ -2,13 +2,6 @@ original file
 -----------------------------------
 interface I {}
 
-const goodHighlighting = <T extends I>(
-  arg: T
-) => {
-  const a = arg
-  return a
-}
-
 const goodHighlighting2 = <
   T
 >(
@@ -46,89 +39,6 @@ Grammar: TypeScript.tmLanguage
 >
  ^
  source.ts
->const goodHighlighting = <T extends I>(
- ^^^^^
- source.ts meta.var.expr.ts storage.type.ts
-      ^
-      source.ts meta.var.expr.ts
-       ^^^^^^^^^^^^^^^^
-       source.ts meta.var.expr.ts meta.var-single-variable.expr.ts meta.definition.variable.ts variable.other.constant.ts entity.name.function.ts
-                       ^
-                       source.ts meta.var.expr.ts meta.var-single-variable.expr.ts
-                        ^
-                        source.ts meta.var.expr.ts keyword.operator.assignment.ts
-                         ^
-                         source.ts meta.var.expr.ts meta.arrow.ts
-                          ^
-                          source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts punctuation.definition.typeparameters.begin.ts
-                           ^
-                           source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts entity.name.type.ts
-                            ^
-                            source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts
-                             ^^^^^^^
-                             source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts storage.modifier.ts
-                                    ^
-                                    source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts
-                                     ^
-                                     source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts entity.name.type.ts
-                                      ^
-                                      source.ts meta.var.expr.ts meta.arrow.ts meta.type.parameters.ts punctuation.definition.typeparameters.end.ts
-                                       ^
-                                       source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.begin.ts
->  arg: T
- ^^
- source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts
-   ^^^
-   source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts variable.parameter.ts
-      ^
-      source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts meta.type.annotation.ts keyword.operator.type.annotation.ts
-       ^
-       source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts meta.type.annotation.ts
-        ^
-        source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts meta.type.annotation.ts entity.name.type.ts
->) => {
- ^
- source.ts meta.var.expr.ts meta.arrow.ts meta.parameters.ts punctuation.definition.parameters.end.ts
-  ^
-  source.ts meta.var.expr.ts meta.arrow.ts
-   ^^
-   source.ts meta.var.expr.ts meta.arrow.ts storage.type.function.arrow.ts
-     ^
-     source.ts meta.var.expr.ts meta.arrow.ts
-      ^
-      source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts punctuation.definition.block.ts
->  const a = arg
- ^^
- source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts
-   ^^^^^
-   source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts storage.type.ts
-        ^
-        source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts
-         ^
-         source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts meta.var-single-variable.expr.ts meta.definition.variable.ts variable.other.constant.ts
-          ^
-          source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts meta.var-single-variable.expr.ts
-           ^
-           source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts keyword.operator.assignment.ts
-            ^
-            source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts
-             ^^^
-             source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts meta.var.expr.ts variable.other.readwrite.ts
->  return a
- ^^
- source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts
-   ^^^^^^
-   source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts keyword.control.flow.ts
-         ^
-         source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts
-          ^
-          source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts variable.other.readwrite.ts
->}
- ^
- source.ts meta.var.expr.ts meta.arrow.ts meta.block.ts punctuation.definition.block.ts
->
- ^
- source.ts
 >const goodHighlighting2 = <
  ^^^^^
  source.ts meta.var.expr.ts storage.type.ts