fix(transform-typescript): do not elide injected imports (#7833)

packages/babel-plugin-transform-typescript/src/index.js

@@ -33,39 +33,42 @@ export default declare(api => {
 
       Program(path, state: State) {
         state.programPath = path;
-      },
 
-      ImportDeclaration(path, state: State) {
-        // Note: this will allow both `import { } from "m"` and `import "m";`.
-        // In TypeScript, the former would be elided.
-        if (path.node.specifiers.length === 0) {
-          return;
-        }
+        // remove type imports
+        for (const stmt of path.get("body")) {
+          if (t.isImportDeclaration(stmt)) {
+            // Note: this will allow both `import { } from "m"` and `import "m";`.
+            // In TypeScript, the former would be elided.
+            if (stmt.node.specifiers.length === 0) {
+              return;
+            }
 
-        let allElided = true;
-        const importsToRemove: Path<Node>[] = [];
+            let allElided = true;
+            const importsToRemove: Path<Node>[] = [];
 
-        for (const specifier of path.node.specifiers) {
-          const binding = path.scope.getBinding(specifier.local.name);
+            for (const specifier of stmt.node.specifiers) {
+              const binding = stmt.scope.getBinding(specifier.local.name);
 
-          // The binding may not exist if the import node was explicitly
-          // injected by another plugin. Currently core does not do a good job
-          // of keeping scope bindings synchronized with the AST. For now we
-          // just bail if there is no binding, since chances are good that if
-          // the import statement was injected then it wasn't a typescript type
-          // import anyway.
-          if (binding && isImportTypeOnly(binding, state.programPath)) {
-            importsToRemove.push(binding.path);
-          } else {
-            allElided = false;
-          }
-        }
+              // The binding may not exist if the import node was explicitly
+              // injected by another plugin. Currently core does not do a good job
+              // of keeping scope bindings synchronized with the AST. For now we
+              // just bail if there is no binding, since chances are good that if
+              // the import statement was injected then it wasn't a typescript type
+              // import anyway.
+              if (binding && isImportTypeOnly(binding, state.programPath)) {
+                importsToRemove.push(binding.path);
+              } else {
+                allElided = false;
+              }
+            }
 
-        if (allElided) {
-          path.remove();
-        } else {
-          for (const importPath of importsToRemove) {
-            importPath.remove();
+            if (allElided) {
+              stmt.remove();
+            } else {
+              for (const importPath of importsToRemove) {
+                importPath.remove();
+              }
+            }
           }
         }
       },

packages/babel-plugin-transform-typescript/test/fixtures/imports/elide-injected/input.mjs

@@ -0,0 +1 @@
+a();

packages/babel-plugin-transform-typescript/test/fixtures/imports/elide-injected/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-typescript", "./plugin"]
+}

packages/babel-plugin-transform-typescript/test/fixtures/imports/elide-injected/output.mjs

@@ -0,0 +1,2 @@
+import local from "source";
+local();

packages/babel-plugin-transform-typescript/test/fixtures/imports/elide-injected/plugin.js

@@ -0,0 +1,26 @@
+module.exports = function({ types: t }) {
+  return {
+    visitor: {
+      CallExpression(path) {
+        if (path.node.callee.name === "a") {
+          // the import we add here should not be elided
+          path.scope
+            .getProgramParent()
+            .path.unshiftContainer(
+              "body",
+              t.importDeclaration(
+                [t.importDefaultSpecifier(t.identifier("local"))],
+                t.stringLiteral("source")
+              )
+            );
+
+          // with this crawl, babel-plugin-transform-typescript
+          // used to elide the import we just added
+          // https://github.com/babel/babel/issues/7592
+          path.scope.crawl();
+          path.node.callee = t.identifier("local");
+        }
+      },
+    },
+  };
+};