1 files changed, 253 insertions, 0 deletions
diff --git a/runtime/js/10_permissions.js b/runtime/js/10_permissions.js
new file mode 100644
index 000000000..a6884aab9
--- /dev/null
+++ b/runtime/js/10_permissions.js
@@ -0,0 +1,253 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+"use strict";
+
+((window) => {
+  const {
+    Event,
+    EventTarget,
+    Deno: { core },
+    __bootstrap: { webUtil: { illegalConstructorKey } },
+  } = window;
+  const { pathFromURL } = window.__bootstrap.util;
+  const {
+    ArrayIsArray,
+    ArrayPrototypeIncludes,
+    ArrayPrototypeMap,
+    ArrayPrototypeSlice,
+    Map,
+    MapPrototypeGet,
+    MapPrototypeHas,
+    MapPrototypeSet,
+    FunctionPrototypeCall,
+    PromiseResolve,
+    PromiseReject,
+    SymbolFor,
+    TypeError,
+  } = window.__bootstrap.primordials;
+
+  /**
+   * @typedef StatusCacheValue
+   * @property {PermissionState} state
+   * @property {PermissionStatus} status
+   */
+
+  /** @type {ReadonlyArray<"read" | "write" | "net" | "env" | "run" | "ffi" | "hrtime">} */
+  const permissionNames = [
+    "read",
+    "write",
+    "net",
+    "env",
+    "run",
+    "ffi",
+    "hrtime",
+  ];
+
+  /**
+   * @param {Deno.PermissionDescriptor} desc
+   * @returns {Deno.PermissionState}
+   */
+  function opQuery(desc) {
+    return core.opSync("op_query_permission", desc);
+  }
+
+  /**
+   * @param {Deno.PermissionDescriptor} desc
+   * @returns {Deno.PermissionState}
+   */
+  function opRevoke(desc) {
+    return core.opSync("op_revoke_permission", desc);
+  }
+
+  /**
+   * @param {Deno.PermissionDescriptor} desc
+   * @returns {Deno.PermissionState}
+   */
+  function opRequest(desc) {
+    return core.opSync("op_request_permission", desc);
+  }
+
+  class PermissionStatus extends EventTarget {
+    /** @type {{ state: Deno.PermissionState }} */
+    #state;
+
+    /** @type {((this: PermissionStatus, event: Event) => any) | null} */
+    onchange = null;
+
+    /** @returns {Deno.PermissionState} */
+    get state() {
+      return this.#state.state;
+    }
+
+    /**
+     * @param {{ state: Deno.PermissionState }} state
+     * @param {unknown} key
+     */
+    constructor(state = null, key = null) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+      super();
+      this.#state = state;
+    }
+
+    /**
+     * @param {Event} event
+     * @returns {boolean}
+     */
+    dispatchEvent(event) {
+      let dispatched = super.dispatchEvent(event);
+      if (dispatched && this.onchange) {
+        FunctionPrototypeCall(this.onchange, this, event);
+        dispatched = !event.defaultPrevented;
+      }
+      return dispatched;
+    }
+
+    [SymbolFor("Deno.privateCustomInspect")](inspect) {
+      return `${this.constructor.name} ${
+        inspect({ state: this.state, onchange: this.onchange })
+      }`;
+    }
+  }
+
+  /** @type {Map<string, StatusCacheValue>} */
+  const statusCache = new Map();
+
+  /**
+   * @param {Deno.PermissionDescriptor} desc
+   * @param {Deno.PermissionState} state
+   * @returns {PermissionStatus}
+   */
+  function cache(desc, state) {
+    let { name: key } = desc;
+    if ((desc.name === "read" || desc.name === "write") && "path" in desc) {
+      key += `-${desc.path}`;
+    } else if (desc.name === "net" && desc.host) {
+      key += `-${desc.host}`;
+    }
+    if (MapPrototypeHas(statusCache, key)) {
+      const status = MapPrototypeGet(statusCache, key);
+      if (status.state !== state) {
+        status.state = state;
+        status.status.dispatchEvent(new Event("change", { cancelable: false }));
+      }
+      return status.status;
+    }
+    /** @type {{ state: Deno.PermissionState; status?: PermissionStatus }} */
+    const status = { state };
+    status.status = new PermissionStatus(status, illegalConstructorKey);
+    MapPrototypeSet(statusCache, key, status);
+    return status.status;
+  }
+
+  /**
+   * @param {unknown} desc
+   * @returns {desc is Deno.PermissionDescriptor}
+   */
+  function isValidDescriptor(desc) {
+    return desc && desc !== null &&
+      ArrayPrototypeIncludes(permissionNames, desc.name);
+  }
+
+  class Permissions {
+    constructor(key = null) {
+      if (key != illegalConstructorKey) {
+        throw new TypeError("Illegal constructor.");
+      }
+    }
+
+    query(desc) {
+      if (!isValidDescriptor(desc)) {
+        return PromiseReject(
+          new TypeError(
+            `The provided value "${desc.name}" is not a valid permission name.`,
+          ),
+        );
+      }
+
+      if (
+        desc.name === "read" || desc.name === "write" || desc.name === "ffi"
+      ) {
+        desc.path = pathFromURL(desc.path);
+      } else if (desc.name === "run") {
+        desc.command = pathFromURL(desc.command);
+      }
+
+      const state = opQuery(desc);
+      return PromiseResolve(cache(desc, state));
+    }
+
+    revoke(desc) {
+      if (!isValidDescriptor(desc)) {
+        return PromiseReject(
+          new TypeError(
+            `The provided value "${desc.name}" is not a valid permission name.`,
+          ),
+        );
+      }
+
+      if (desc.name === "read" || desc.name === "write") {
+        desc.path = pathFromURL(desc.path);
+      } else if (desc.name === "run") {
+        desc.command = pathFromURL(desc.command);
+      }
+
+      const state = opRevoke(desc);
+      return PromiseResolve(cache(desc, state));
+    }
+
+    request(desc) {
+      if (!isValidDescriptor(desc)) {
+        return PromiseReject(
+          new TypeError(
+            `The provided value "${desc.name}" is not a valid permission name.`,
+          ),
+        );
+      }
+
+      if (desc.name === "read" || desc.name === "write") {
+        desc.path = pathFromURL(desc.path);
+      } else if (desc.name === "run") {
+        desc.command = pathFromURL(desc.command);
+      }
+
+      const state = opRequest(desc);
+      return PromiseResolve(cache(desc, state));
+    }
+  }
+
+  const permissions = new Permissions(illegalConstructorKey);
+
+  /** Converts all file URLs in FS allowlists to paths. */
+  function serializePermissions(permissions) {
+    if (typeof permissions == "object" && permissions != null) {
+      const serializedPermissions = {};
+      for (const key of ["read", "write", "run", "ffi"]) {
+        if (ArrayIsArray(permissions[key])) {
+          serializedPermissions[key] = ArrayPrototypeMap(
+            permissions[key],
+            (path) => pathFromURL(path),
+          );
+        } else {
+          serializedPermissions[key] = permissions[key];
+        }
+      }
+      for (const key of ["env", "hrtime", "net"]) {
+        if (ArrayIsArray(permissions[key])) {
+          serializedPermissions[key] = ArrayPrototypeSlice(permissions[key]);
+        } else {
+          serializedPermissions[key] = permissions[key];
+        }
+      }
+      return serializedPermissions;
+    }
+    return permissions;
+  }
+
+  window.__bootstrap.permissions = {
+    serializePermissions,
+    permissions,
+    Permissions,
+    PermissionStatus,
+  };
+})(this);