WIP - add extractor, generate snippet_data

node_modules/babel-plugin-minify-dead-code-elimination/lib/remove-use-strict.js

@@ -0,0 +1,54 @@
+"use strict";
+
+module.exports = removeUseStrict;
+
+var newIssueUrl = "https://github.com/babel/minify/issues/new";
+
+var useStrict = "use strict";
+
+/**
+ * Remove redundant use strict
+ * If the parent has a "use strict" directive, it is not required in
+ * the children
+ *
+ * @param {NodePath} block BlockStatement
+ */
+function removeUseStrict(block) {
+  if (!block.isBlockStatement()) {
+    throw new Error(`Received ${block.type}. Expected BlockStatement. ` + `Please report at ${newIssueUrl}`);
+  }
+
+  var useStricts = getUseStrictDirectives(block);
+
+  // early exit
+  if (useStricts.length < 1) return;
+
+  // only keep the first use strict
+  if (useStricts.length > 1) {
+    for (var i = 1; i < useStricts.length; i++) {
+      useStricts[i].remove();
+    }
+  }
+
+  // check if parent has an use strict
+  if (hasStrictParent(block)) {
+    useStricts[0].remove();
+  }
+}
+
+function hasStrictParent(path) {
+  return path.findParent(function (parent) {
+    return parent.isBlockStatement() && isStrict(parent);
+  });
+}
+
+function isStrict(block) {
+  return getUseStrictDirectives(block).length > 0;
+}
+
+function getUseStrictDirectives(block) {
+  var dir = block.get("directives");
+  return Array.isArray(dir) ? dir.filter(function (directive) {
+    return directive.node.value.value === useStrict;
+  }) : [];
+}