1 files changed, 232 insertions, 0 deletions
diff --git a/node_modules/esm-import-transformer/import-transformer.js b/node_modules/esm-import-transformer/import-transformer.js
new file mode 100644
index 0000000..4b09aa1
--- /dev/null
+++ b/node_modules/esm-import-transformer/import-transformer.js
@@ -0,0 +1,232 @@
+import { parse } from "acorn";
+
+const COMMENT_START = "/* ";
+const COMMENT_END = " */";
+const EXPORT_STR = "export ";
+
+export class ImportTransformer {
+  constructor(input, ast) {
+    this.parse(input, ast);
+  }
+
+  parse(input, ast) {
+    if(!input) {
+      throw new Error("Missing input to ImportTransformer, received: " + input)
+    }
+
+    this.originalSource = input;
+
+    if(ast) {
+      this.ast = ast;
+    } else {
+      this.ast = parse(input, {
+        sourceType: "module",
+        ecmaVersion: "latest"
+      });
+    }
+
+    this.imports = new Set();
+    this.exports = new Set();
+    this.namedExports = new Set();
+  }
+
+  static commentNode(str, sourceNode, indexOffset = 0) {
+    let { start, end } = sourceNode;
+    let statement = str.slice(start + indexOffset, end + indexOffset);
+    return {
+      statement,
+      code: `${str.slice(0, start + indexOffset)}${COMMENT_START}${statement}${COMMENT_END}${str.slice(end + indexOffset)}`,
+      offset: COMMENT_START.length + COMMENT_END.length,
+    };
+  }
+
+  static commentExportDeclarationOnly(str, sourceNode, indexOffset = 0) {
+    let { start, end } = sourceNode;
+    let statement = str.slice(start + indexOffset, end + indexOffset);
+
+    let functionDeclarationName = sourceNode.declaration?.id?.name;
+    let variableIdentifierNames = (sourceNode.declaration?.declarations || []).map(node => {
+      if(node.id.properties) {
+        return node.id.properties.map(node => node.key.name)
+      } else if(node.id.name) {
+        return node.id.name;
+      }
+
+      throw new Error("Could not find variable identifier in declaration for: " + statement);
+    }).flat();
+
+    let reuseStatement;
+    // change `export const a = 1;` to `export { a };` for reuse
+    if(functionDeclarationName || variableIdentifierNames.length > 0) {
+      reuseStatement = `export { ${functionDeclarationName || variableIdentifierNames.join(", ") } };`;
+    } else {
+      throw new Error("Couldn’t find identifier name for: " + statement);
+    }
+
+    // -1 there removes the double space between `export ` and ` */`
+    let commented = `${COMMENT_START}${EXPORT_STR.slice(0, -1)}${COMMENT_END}${statement.slice(EXPORT_STR.length)}`
+    return {
+      statement: reuseStatement,
+      namedExports: functionDeclarationName ? [functionDeclarationName] : variableIdentifierNames,
+      code: `${str.slice(0, start + indexOffset)}${commented}${str.slice(end + indexOffset)}`,
+      offset: COMMENT_START.length + COMMENT_END.length - 1, // -1 removes the double space between `export ` and ` */`
+    };
+  }
+
+  static transformImportSource(str, sourceNode, indexOffset = 0, importMap = {}) {
+    let { start, end, value } = sourceNode;
+    // Could be improved by https://www.npmjs.com/package/@import-maps/resolve
+    let resolved = importMap?.imports && importMap?.imports[value];
+    if(resolved) {
+      return {
+        code: `${str.slice(0, start + 1 + indexOffset)}${resolved}${str.slice(end - 1 + indexOffset)}`,
+        offset: resolved.length - value.length,
+      };
+    }
+    return {
+      code: str,
+      offset: 0
+    };
+  }
+
+  static transformImportCode(prefix, str, node, specifiers, sourceNode, indexOffset = 0) {
+    let { start, end } = node;
+    let endOffset = end - sourceNode.end;
+
+    start += indexOffset;
+    end += indexOffset;
+
+    let { raw: rawSourceValue } = sourceNode;
+    let importDeclaration = str.slice(start, end);
+
+    let specifierIndexes = [];
+    if(importDeclaration.startsWith("import * as ")) {
+      specifierIndexes[0] = "import * as ".length + start;
+    } else if(importDeclaration.startsWith("import ")) {
+      specifierIndexes[0] = "import ".length + start;
+    } else {
+      throw new Error(`Could not find \`import\` in import declaration: ${importDeclaration}`);
+    }
+
+    specifierIndexes[1] = specifiers[specifiers.length - 1].end + indexOffset;
+
+    // normalize away trailing } on import { a, b, c } specifiers
+    let split = str.slice(specifierIndexes[1]).split(" from ");
+    if(split.length > 0) {
+      specifierIndexes[1] += split[0].length;
+    }
+
+    let newImportString = `const ${str.slice(specifierIndexes[0], specifierIndexes[1])} = ${prefix}(${rawSourceValue})`;
+    let returnedCode = str.slice(0, start) + newImportString + str.slice(end - endOffset);
+
+    return {
+      code: returnedCode,
+      offset: returnedCode.length - str.length,
+    };
+  }
+
+  _transform(prefix) {
+    let input = this.originalSource;
+    let indexOffset = 0;
+    for(let node of this.ast.body) {
+      if(node.type === "ImportDeclaration") {
+        let ret = ImportTransformer.transformImportCode(prefix, input, node, node.specifiers, node.source, indexOffset)
+        input = ret.code;
+        indexOffset += ret.offset;
+      }
+    }
+
+    return input;
+  }
+
+  transformToDynamicImport() {
+    return this._transform("await import");
+  }
+
+  transformToRequire() {
+    return this._transform("require");
+  }
+
+  // alias for backwards compat
+  transform(...args) {
+    return this.transformWithImportMap(...args);
+  }
+
+  transformRemoveImportExports() {
+    let input = this.originalSource;
+    let indexOffset = 0;
+    for(let node of this.ast.body) {
+      if(node.type === "ImportDeclaration") {
+        let ret = ImportTransformer.commentNode(input, node, indexOffset);
+        input = ret.code;
+        indexOffset += ret.offset;
+        this.imports.add(ret.statement);
+      } else if(node.type?.startsWith("Export")) {
+        let ret;
+        // comment out `export { name }` and `export default`
+        if(node.type === "ExportNamedDeclaration" && node.specifiers.length > 0 || node.type === "ExportDefaultDeclaration") {
+          ret = ImportTransformer.commentNode(input, node, indexOffset);
+          if(node.type === "ExportDefaultDeclaration") {
+            this.namedExports.add("default");
+          } else {
+            for(let specifierNode of node.specifiers || []) {
+              if(specifierNode?.exported?.name) {
+                this.namedExports.add(specifierNode.exported.name);
+              }
+            }
+          }
+        } else {
+          // just comment out start `export ` from the beginning of `export const` or `export function`
+          ret = ImportTransformer.commentExportDeclarationOnly(input, node, indexOffset);
+          for(let name of ret.namedExports) {
+            this.namedExports.add(name);
+          }
+        }
+
+        input = ret.code;
+        indexOffset += ret.offset;
+        this.exports.add(ret.statement);
+      }
+    }
+
+    return input;
+  }
+
+  getImportsAndExports() {
+    return {
+      imports: this.imports,
+      exports: this.exports,
+      namedExports: this.namedExports,
+    };
+  }
+
+  transformWithImportMap(importMap) {
+    if(!importMap) {
+      return this.originalSource;
+    }
+
+    let input = this.originalSource;
+    let indexOffset = 0;
+    for(let node of this.ast.body) {
+      if(node.type === "ImportDeclaration") {
+        if(importMap?.imports) {
+          let ret = ImportTransformer.transformImportSource(input, node.source, indexOffset, importMap);
+          input = ret.code;
+          indexOffset += ret.offset;
+        }
+      }
+    }
+
+    return input;
+  }
+
+  hasImports() {
+    for(let node of this.ast.body) {
+      if(node.type === "ImportDeclaration") {
+        return true;
+      }
+    }
+
+    return false;
+  }
+}