rename flow-comments plugin

packages/babel-plugin-transform-flow-comments/src/index.js

@@ -0,0 +1,59 @@
+export default function ({ types: t }) {
+  function wrapInFlowComment(path, parent) {
+    path.addComment("trailing", generateComment(path, parent));
+    path.replaceWith(t.noop());
+  }
+
+  function generateComment(path, parent) {
+    let comment = path.getSource().replace(/\*-\//g, "*-ESCAPED/").replace(/\*\//g, "*-/");
+    if (parent && parent.optional) comment = "?" + comment;
+    if (comment[0] !== ":") comment = ":: " + comment;
+    return comment;
+  }
+
+  return {
+    inherits: require("babel-plugin-syntax-flow"),
+
+    visitor: {
+      TypeCastExpression(path) {
+        let { node } = path;
+        path.get("expression").addComment("trailing", generateComment(path.get("typeAnnotation")));
+        path.replaceWith(t.parenthesizedExpression(node.expression));
+      },
+
+      // support function a(b?) {}
+      Identifier(path) {
+        let { node } = path;
+        if (!node.optional || node.typeAnnotation) {
+          return;
+        }
+        path.addComment("trailing", ":: ?");
+      },
+
+      // strip optional property from function params - facebook/fbjs#17
+      Function: {
+        exit({ node }) {
+          node.params.forEach(param => param.optional = false);
+        }
+      },
+
+      // support `export type a = {}` - #8 Error: You passed path.replaceWith() a falsy node
+      "ExportNamedDeclaration|Flow"(path) {
+        let { node, parent } = path;
+        if (t.isExportNamedDeclaration(node) && !t.isFlow(node.declaration)) {
+          return;
+        }
+        wrapInFlowComment(path, parent);
+      },
+
+      // support `import type A` and `import typeof A` #10
+      ImportDeclaration(path) {
+        let { node, parent } = path;
+        if (t.isImportDeclaration(node) && node.importKind !== "type" && node.importKind !== "typeof") {
+          return;
+        }
+        wrapInFlowComment(path, parent);
+      }
+    }
+  };
+}