Fix flow comments plugin issues (#10329)

* Fix issues in flow-comments to preserve comments and there order (fixes #10324)

* Add support in flow-comments for extends in class declarations (fixes #10323, #10321)

* Refactoring and cleanup of flow-comments plugin

* Fix comments preservation logic of flow-comments

* Fix flow-comments where comments are class identifier and extends keyword

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-extends-type-parameter/input.js

@@ -0,0 +1 @@
+class Foo extends Bar<T> {}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-extends-type-parameter/output.js

@@ -0,0 +1,3 @@
+class Foo extends Bar
+/*:: <T>*/
+{}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-type-parameter-extends-type-parameter/input.js

@@ -0,0 +1,3 @@
+class Foo<T> /* inner */ extends Bar<R> {}
+
+/*a*/class /*b*/Baz/*c*/<T>/*d*/extends /*e*/Bar/*f*/<R>/*g*/ {/*h*/}/*i*/

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-type-parameter-extends-type-parameter/output.js

@@ -0,0 +1,30 @@
+class Foo
+/*:: <T>*/
+
+/* inner */
+extends Bar
+/*:: <R>*/
+{}
+/*a*/
+
+
+class
+/*b*/
+Baz
+/*c*/
+
+/*:: <T>*/
+
+/*d*/
+extends
+/*e*/
+Bar
+/*f*/
+
+/*:: <R>*/
+
+/*g*/
+{}
+/*h*/
+
+/*i*/

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-type-parameter-extends/input.js

@@ -0,0 +1 @@
+class Foo<T> extends Bar {}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-type-parameter-extends/output.js

@@ -0,0 +1,3 @@
+class Foo
+/*:: <T>*/
+extends Bar {}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/preserve-comments-order/input.js

@@ -0,0 +1,7 @@
+/*a*/
+type Foo = number;
+/*b*/
+var foo;
+/*c*/
+type Bar = number;
+/*d*/

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/preserve-comments-order/output.js

@@ -0,0 +1,11 @@
+/*a*/
+
+/*:: type Foo = number;*/
+
+/*b*/
+var foo;
+/*c*/
+
+/*:: type Bar = number;*/
+
+/*d*/

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/preserve-comments/input.js

@@ -0,0 +1,2 @@
+/**/
+type Foo = number;

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/preserve-comments/output.js

@@ -0,0 +1,3 @@
+/**/
+
+/*:: type Foo = number;*/