1 files changed, 251 insertions, 0 deletions
diff --git a/std/fs/expand_glob.ts b/std/fs/expand_glob.ts
new file mode 100644
index 000000000..c43e09d40
--- /dev/null
+++ b/std/fs/expand_glob.ts
@@ -0,0 +1,251 @@
+import {
+  GlobOptions,
+  SEP_PATTERN,
+  globToRegExp,
+  isAbsolute,
+  isGlob,
+  isWindows,
+  joinGlobs,
+  normalize
+} from "../path/mod.ts";
+import { WalkInfo, walk, walkSync } from "./walk.ts";
+const { cwd, stat, statSync } = Deno;
+type FileInfo = Deno.FileInfo;
+
+export interface ExpandGlobOptions extends GlobOptions {
+  root?: string;
+  exclude?: string[];
+  includeDirs?: boolean;
+}
+
+interface SplitPath {
+  segments: string[];
+  isAbsolute: boolean;
+  hasTrailingSep: boolean;
+  // Defined for any absolute Windows path.
+  winRoot?: string;
+}
+
+// TODO: Maybe make this public somewhere.
+function split(path: string): SplitPath {
+  const s = SEP_PATTERN.source;
+  const segments = path
+    .replace(new RegExp(`^${s}|${s}$`, "g"), "")
+    .split(SEP_PATTERN);
+  const isAbsolute_ = isAbsolute(path);
+  return {
+    segments,
+    isAbsolute: isAbsolute_,
+    hasTrailingSep: !!path.match(new RegExp(`${s}$`)),
+    winRoot: isWindows && isAbsolute_ ? segments.shift() : undefined
+  };
+}
+
+/**
+ * Expand the glob string from the specified `root` directory and yield each
+ * result as a `WalkInfo` object.
+ */
+// TODO: Use a proper glob expansion algorithm.
+// This is a very incomplete solution. The whole directory tree from `root` is
+// walked and parent paths are not supported.
+export async function* expandGlob(
+  glob: string,
+  {
+    root = cwd(),
+    exclude = [],
+    includeDirs = true,
+    extended = false,
+    globstar = false
+  }: ExpandGlobOptions = {}
+): AsyncIterableIterator<WalkInfo> {
+  const globOptions: GlobOptions = { extended, globstar };
+  const absRoot = isAbsolute(root)
+    ? normalize(root)
+    : joinGlobs([cwd(), root], globOptions);
+  const resolveFromRoot = (path: string): string =>
+    isAbsolute(path)
+      ? normalize(path)
+      : joinGlobs([absRoot, path], globOptions);
+  const excludePatterns = exclude
+    .map(resolveFromRoot)
+    .map((s: string): RegExp => globToRegExp(s, globOptions));
+  const shouldInclude = ({ filename }: WalkInfo): boolean =>
+    !excludePatterns.some((p: RegExp): boolean => !!filename.match(p));
+  const { segments, hasTrailingSep, winRoot } = split(resolveFromRoot(glob));
+
+  let fixedRoot = winRoot != undefined ? winRoot : "/";
+  while (segments.length > 0 && !isGlob(segments[0])) {
+    fixedRoot = joinGlobs([fixedRoot, segments.shift()!], globOptions);
+  }
+
+  let fixedRootInfo: WalkInfo;
+  try {
+    fixedRootInfo = { filename: fixedRoot, info: await stat(fixedRoot) };
+  } catch {
+    return;
+  }
+
+  async function* advanceMatch(
+    walkInfo: WalkInfo,
+    globSegment: string
+  ): AsyncIterableIterator<WalkInfo> {
+    if (!walkInfo.info.isDirectory()) {
+      return;
+    } else if (globSegment == "..") {
+      const parentPath = joinGlobs([walkInfo.filename, ".."], globOptions);
+      try {
+        return yield* [
+          { filename: parentPath, info: await stat(parentPath) }
+        ].filter(shouldInclude);
+      } catch {
+        return;
+      }
+    } else if (globSegment == "**") {
+      return yield* walk(walkInfo.filename, {
+        includeFiles: false,
+        skip: excludePatterns
+      });
+    }
+    yield* walk(walkInfo.filename, {
+      maxDepth: 1,
+      match: [
+        globToRegExp(
+          joinGlobs([walkInfo.filename, globSegment], globOptions),
+          globOptions
+        )
+      ],
+      skip: excludePatterns
+    });
+  }
+
+  let currentMatches: WalkInfo[] = [fixedRootInfo];
+  for (const segment of segments) {
+    // Advancing the list of current matches may introduce duplicates, so we
+    // pass everything through this Map.
+    const nextMatchMap: Map<string, FileInfo> = new Map();
+    for (const currentMatch of currentMatches) {
+      for await (const nextMatch of advanceMatch(currentMatch, segment)) {
+        nextMatchMap.set(nextMatch.filename, nextMatch.info);
+      }
+    }
+    currentMatches = [...nextMatchMap].sort().map(
+      ([filename, info]): WalkInfo => ({
+        filename,
+        info
+      })
+    );
+  }
+  if (hasTrailingSep) {
+    currentMatches = currentMatches.filter(
+      ({ info }): boolean => info.isDirectory()
+    );
+  }
+  if (!includeDirs) {
+    currentMatches = currentMatches.filter(
+      ({ info }): boolean => !info.isDirectory()
+    );
+  }
+  yield* currentMatches;
+}
+
+/** Synchronous version of `expandGlob()`. */
+// TODO: As `expandGlob()`.
+export function* expandGlobSync(
+  glob: string,
+  {
+    root = cwd(),
+    exclude = [],
+    includeDirs = true,
+    extended = false,
+    globstar = false
+  }: ExpandGlobOptions = {}
+): IterableIterator<WalkInfo> {
+  const globOptions: GlobOptions = { extended, globstar };
+  const absRoot = isAbsolute(root)
+    ? normalize(root)
+    : joinGlobs([cwd(), root], globOptions);
+  const resolveFromRoot = (path: string): string =>
+    isAbsolute(path)
+      ? normalize(path)
+      : joinGlobs([absRoot, path], globOptions);
+  const excludePatterns = exclude
+    .map(resolveFromRoot)
+    .map((s: string): RegExp => globToRegExp(s, globOptions));
+  const shouldInclude = ({ filename }: WalkInfo): boolean =>
+    !excludePatterns.some((p: RegExp): boolean => !!filename.match(p));
+  const { segments, hasTrailingSep, winRoot } = split(resolveFromRoot(glob));
+
+  let fixedRoot = winRoot != undefined ? winRoot : "/";
+  while (segments.length > 0 && !isGlob(segments[0])) {
+    fixedRoot = joinGlobs([fixedRoot, segments.shift()!], globOptions);
+  }
+
+  let fixedRootInfo: WalkInfo;
+  try {
+    fixedRootInfo = { filename: fixedRoot, info: statSync(fixedRoot) };
+  } catch {
+    return;
+  }
+
+  function* advanceMatch(
+    walkInfo: WalkInfo,
+    globSegment: string
+  ): IterableIterator<WalkInfo> {
+    if (!walkInfo.info.isDirectory()) {
+      return;
+    } else if (globSegment == "..") {
+      const parentPath = joinGlobs([walkInfo.filename, ".."], globOptions);
+      try {
+        return yield* [
+          { filename: parentPath, info: statSync(parentPath) }
+        ].filter(shouldInclude);
+      } catch {
+        return;
+      }
+    } else if (globSegment == "**") {
+      return yield* walkSync(walkInfo.filename, {
+        includeFiles: false,
+        skip: excludePatterns
+      });
+    }
+    yield* walkSync(walkInfo.filename, {
+      maxDepth: 1,
+      match: [
+        globToRegExp(
+          joinGlobs([walkInfo.filename, globSegment], globOptions),
+          globOptions
+        )
+      ],
+      skip: excludePatterns
+    });
+  }
+
+  let currentMatches: WalkInfo[] = [fixedRootInfo];
+  for (const segment of segments) {
+    // Advancing the list of current matches may introduce duplicates, so we
+    // pass everything through this Map.
+    const nextMatchMap: Map<string, FileInfo> = new Map();
+    for (const currentMatch of currentMatches) {
+      for (const nextMatch of advanceMatch(currentMatch, segment)) {
+        nextMatchMap.set(nextMatch.filename, nextMatch.info);
+      }
+    }
+    currentMatches = [...nextMatchMap].sort().map(
+      ([filename, info]): WalkInfo => ({
+        filename,
+        info
+      })
+    );
+  }
+  if (hasTrailingSep) {
+    currentMatches = currentMatches.filter(
+      ({ info }): boolean => info.isDirectory()
+    );
+  }
+  if (!includeDirs) {
+    currentMatches = currentMatches.filter(
+      ({ info }): boolean => !info.isDirectory()
+    );
+  }
+  yield* currentMatches;
+}