v0.8.18

• Fix a bug with certain complex optional chains (#573)

  The ?. optional chaining operator only runs the right side of the operator if the left side is undefined, otherwise it returns undefined. This operator can be applied to both property accesses and function calls, and these can be combined into long chains of operators. These expressions must be transformed to a chain of ?: operators if the ?. operator isn't supported in the configured target environment. However, esbuild had a bug where an optional call of an optional property with a further property access afterward didn't preserve the value of this for the call. This bug has been fixed.

• Fix a renaming bug with external imports

  There was a possibility of a cross-module name collision while bundling in a certain edge case. Specifically, when multiple files both contained an import statement to an external module and then both of those files were imported using require. For example:

  // index.js
  console.log(require('./a.js'), require('./b.js'))

  // a.js
  export {exists} from 'fs'

  // b.js
  export {exists} from 'fs'

  In this case the files a.js and b.js are converted to CommonJS format so they can be imported using require:

  // a.js
  import {exists} from "fs";
  var require_a = __commonJS((exports) => {
    __export(exports, {
      exists: () => exists
    });
  });
  
  // b.js
  import {exists} from "fs";
  var require_b = __commonJS((exports) => {
    __export(exports, {
      exists: () => exists
    });
  });
  
  // index.js
  console.log(require_a(), require_b());

  However, the exists symbol has been duplicated without being renamed. This is will result in a syntax error at run-time. The reason this happens is that the statements in the files a.js and b.js are placed in a nested scope because they are inside the CommonJS closure. The import statements were extracted outside the closure but the symbols they declared were incorrectly not added to the outer scope. This problem has been fixed, and this edge case should no longer result in name collisions.