merge completed... now to fix all the bugs...

node_modules/tsconfig-paths/src/match-path-async.ts

@@ -0,0 +1,223 @@
+import * as path from "path";
+import * as TryPath from "./try-path";
+import * as MappingEntry from "./mapping-entry";
+import * as Filesystem from "./filesystem";
+
+/**
+ * Function that can match a path async
+ */
+export interface MatchPathAsync {
+  (
+    requestedModule: string,
+    readJson: Filesystem.ReadJsonAsync | undefined,
+    fileExists: Filesystem.FileExistsAsync | undefined,
+    extensions: ReadonlyArray<string> | undefined,
+    callback: MatchPathAsyncCallback
+  ): void;
+}
+
+export interface MatchPathAsyncCallback {
+  (err?: Error, path?: string): void;
+}
+
+/**
+ * See the sync version for docs.
+ */
+export function createMatchPathAsync(
+  absoluteBaseUrl: string,
+  paths: { [key: string]: Array<string> },
+  mainFields: string[] = ["main"],
+  addMatchAll: boolean = true
+): MatchPathAsync {
+  const absolutePaths = MappingEntry.getAbsoluteMappingEntries(
+    absoluteBaseUrl,
+    paths,
+    addMatchAll
+  );
+
+  return (
+    requestedModule: string,
+    readJson: Filesystem.ReadJsonAsync | undefined,
+    fileExists: Filesystem.FileExistsAsync | undefined,
+    extensions: ReadonlyArray<string> | undefined,
+    callback: MatchPathAsyncCallback
+  ) =>
+    matchFromAbsolutePathsAsync(
+      absolutePaths,
+      requestedModule,
+      readJson,
+      fileExists,
+      extensions,
+      callback,
+      mainFields
+    );
+}
+
+/**
+ * See the sync version for docs.
+ */
+export function matchFromAbsolutePathsAsync(
+  absolutePathMappings: ReadonlyArray<MappingEntry.MappingEntry>,
+  requestedModule: string,
+  readJson: Filesystem.ReadJsonAsync = Filesystem.readJsonFromDiskAsync,
+  fileExists: Filesystem.FileExistsAsync = Filesystem.fileExistsAsync,
+  extensions: ReadonlyArray<string> = Object.keys(require.extensions),
+  callback: MatchPathAsyncCallback,
+  mainFields: string[] = ["main"]
+): void {
+  const tryPaths = TryPath.getPathsToTry(
+    extensions,
+    absolutePathMappings,
+    requestedModule
+  );
+
+  if (!tryPaths) {
+    return callback();
+  }
+
+  findFirstExistingPath(
+    tryPaths,
+    readJson,
+    fileExists,
+    callback,
+    0,
+    mainFields
+  );
+}
+
+function findFirstExistingMainFieldMappedFile(
+  packageJson: Filesystem.PackageJson,
+  mainFields: string[],
+  packageJsonPath: string,
+  fileExistsAsync: Filesystem.FileExistsAsync,
+  doneCallback: (err?: Error, filepath?: string) => void,
+  index: number = 0
+): void {
+  if (index >= mainFields.length) {
+    return doneCallback(undefined, undefined);
+  }
+
+  const tryNext = () =>
+    findFirstExistingMainFieldMappedFile(
+      packageJson,
+      mainFields,
+      packageJsonPath,
+      fileExistsAsync,
+      doneCallback,
+      index + 1
+    );
+
+  const mainFieldMapping = packageJson[mainFields[index]];
+  if (typeof mainFieldMapping !== "string") {
+    // Skip mappings that are not pointers to replacement files
+    return tryNext();
+  }
+
+  const mappedFilePath = path.join(
+    path.dirname(packageJsonPath),
+    mainFieldMapping
+  );
+  fileExistsAsync(mappedFilePath, (err?: Error, exists?: boolean) => {
+    if (err) {
+      return doneCallback(err);
+    }
+    if (exists) {
+      return doneCallback(undefined, mappedFilePath);
+    }
+    return tryNext();
+  });
+}
+
+// Recursive loop to probe for physical files
+function findFirstExistingPath(
+  tryPaths: ReadonlyArray<TryPath.TryPath>,
+  readJson: Filesystem.ReadJsonAsync,
+  fileExists: Filesystem.FileExistsAsync,
+  doneCallback: MatchPathAsyncCallback,
+  index: number = 0,
+  mainFields: string[] = ["main"]
+): void {
+  const tryPath = tryPaths[index];
+  if (
+    tryPath.type === "file" ||
+    tryPath.type === "extension" ||
+    tryPath.type === "index"
+  ) {
+    fileExists(tryPath.path, (err: Error, exists: boolean) => {
+      if (err) {
+        return doneCallback(err);
+      }
+      if (exists) {
+        // Not sure why we don't just return the full path? Why strip it?
+        return doneCallback(undefined, TryPath.getStrippedPath(tryPath));
+      }
+      if (index === tryPaths.length - 1) {
+        return doneCallback();
+      }
+      // Continue with the next path
+      return findFirstExistingPath(
+        tryPaths,
+        readJson,
+        fileExists,
+        doneCallback,
+        index + 1,
+        mainFields
+      );
+    });
+  } else if (tryPath.type === "package") {
+    readJson(tryPath.path, (err, packageJson) => {
+      if (err) {
+        return doneCallback(err);
+      }
+      if (packageJson) {
+        return findFirstExistingMainFieldMappedFile(
+          packageJson,
+          mainFields,
+          tryPath.path,
+          fileExists,
+          (mainFieldErr?: Error, mainFieldMappedFile?: string) => {
+            if (mainFieldErr) {
+              return doneCallback(mainFieldErr);
+            }
+            if (mainFieldMappedFile) {
+              // Not sure why we don't just return the full path? Why strip it?
+              return doneCallback(
+                undefined,
+                Filesystem.removeExtension(mainFieldMappedFile)
+              );
+            }
+
+            // No field in package json was a valid option. Continue with the next path.
+            return findFirstExistingPath(
+              tryPaths,
+              readJson,
+              fileExists,
+              doneCallback,
+              index + 1,
+              mainFields
+            );
+          }
+        );
+      }
+
+      // This is async code, we need to return unconditionally, otherwise the code still falls
+      // through and keeps recursing. While this might work in general, libraries that use neo-async
+      // like Webpack will actually not allow you to call the same callback twice.
+      //
+      // An example of where this caused issues:
+      // https://github.com/dividab/tsconfig-paths-webpack-plugin/issues/11
+      //
+      // Continue with the next path
+      return findFirstExistingPath(
+        tryPaths,
+        readJson,
+        fileExists,
+        doneCallback,
+        index + 1,
+        mainFields
+      );
+    });
+  } else {
+    TryPath.exhaustiveTypeException(tryPath.type);
+  }
+}