Simplify type checking for objects

packages/bulk-edit/src/browser/bulk-edit-tree/bulk-edit-node-selection.ts

@@ -17,13 +17,14 @@
 import { SelectionService } from '@theia/core/lib/common/selection-service';
 import { SelectionCommandHandler } from '@theia/core/lib/common/selection-command-handler';
 import { ResourceFileEdit, ResourceTextEdit } from '@theia/monaco-editor-core/esm/vs/editor/browser/services/bulkEditService';
+import { isObject } from '@theia/core/lib/common';
 
 export interface BulkEditNodeSelection {
     bulkEdit: ResourceFileEdit | ResourceTextEdit;
 }
 export namespace BulkEditNodeSelection {
     export function is(arg: unknown): arg is BulkEditNodeSelection {
-        return !!arg && typeof arg === 'object' && ('bulkEdit' in arg);
+        return isObject(arg) && 'bulkEdit' in arg;
     }
 
     export class CommandHandler extends SelectionCommandHandler<BulkEditNodeSelection> {

packages/core/shared/reflect-metadata/index.d.ts

@@ -0,0 +1 @@
+export * from 'reflect-metadata';

packages/core/shared/reflect-metadata/index.js

@@ -0,0 +1 @@
+module.exports = require('reflect-metadata');

packages/core/src/browser/frontend-application.ts

@@ -15,7 +15,7 @@
 // *****************************************************************************
 
 import { inject, injectable, named } from 'inversify';
-import { ContributionProvider, CommandRegistry, MenuModelRegistry, isOSX, BackendStopwatch, LogLevel, Stopwatch } from '../common';
+import { ContributionProvider, CommandRegistry, MenuModelRegistry, isOSX, BackendStopwatch, LogLevel, Stopwatch, isObject } from '../common';
 import { MaybePromise } from '../common/types';
 import { KeybindingRegistry } from './keybinding';
 import { Widget } from './widgets';
@@ -101,7 +101,7 @@ export interface OnWillStopAction<T = unknown> {
 
 export namespace OnWillStopAction {
     export function is(candidate: unknown): candidate is OnWillStopAction {
-        return typeof candidate === 'object' && !!candidate && 'action' in candidate && 'reason' in candidate;
+        return isObject(candidate) && 'action' in candidate && 'reason' in candidate;
     }
 }
 

packages/core/src/browser/label-parser.ts

@@ -14,15 +14,16 @@
 // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 // *****************************************************************************
 import { injectable } from 'inversify';
+import { isObject, isString } from '../common';
 
 export interface LabelIcon {
     name: string;
     animation?: string;
 }
 
 export namespace LabelIcon {
-    export function is(val: object): val is LabelIcon {
-        return 'name' in val;
+    export function is(val: unknown): val is LabelIcon {
+        return isObject<LabelIcon>(val) && isString(val.name);
     }
 }
 

packages/core/src/browser/label-provider.ts

@@ -18,8 +18,7 @@ import { inject, injectable, named, postConstruct } from 'inversify';
 import * as fileIcons from 'file-icons-js';
 import URI from '../common/uri';
 import { ContributionProvider } from '../common/contribution-provider';
-import { Prioritizeable } from '../common/types';
-import { Event, Emitter, Disposable, Path } from '../common';
+import { Event, Emitter, Disposable, isObject, Path, Prioritizeable } from '../common';
 import { FrontendApplicationContribution } from './frontend-application';
 import { EnvVariablesServer } from '../common/env-variables/env-variables-protocol';
 import { ResourceLabelFormatter, ResourceLabelFormatting } from '../common/label-protocol';
@@ -99,7 +98,7 @@ export interface URIIconReference {
 }
 export namespace URIIconReference {
     export function is(element: unknown): element is URIIconReference {
-        return !!element && typeof element === 'object' && 'kind' in element && (element as URIIconReference).kind === 'uriIconReference';
+        return isObject(element) && element.kind === 'uriIconReference';
     }
     export function create(id: URIIconReference['id'], uri?: URI): URIIconReference {
         return { kind: 'uriIconReference', id, uri };

packages/core/src/browser/navigatable-types.ts

@@ -14,8 +14,7 @@
 // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 // *****************************************************************************
 
-import URI from '../common/uri';
-import { MaybeArray } from '../common/types';
+import { URI, isObject, MaybeArray } from '../common';
 import { Widget, BaseWidget } from './widgets';
 
 /**
@@ -34,7 +33,7 @@ export interface Navigatable {
 
 export namespace Navigatable {
     export function is(arg: unknown): arg is Navigatable {
-        return !!arg && typeof arg === 'object' && 'getResourceUri' in arg && 'createMoveToUri' in arg;
+        return isObject(arg) && 'getResourceUri' in arg && 'createMoveToUri' in arg;
     }
 }
 
@@ -71,12 +70,12 @@ export namespace NavigatableWidget {
 }
 
 export interface NavigatableWidgetOptions {
-    kind: 'navigatable',
-    uri: string,
-    counter?: number,
+    kind: 'navigatable';
+    uri: string;
+    counter?: number;
 }
 export namespace NavigatableWidgetOptions {
     export function is(arg: unknown): arg is NavigatableWidgetOptions {
-        return !!arg && typeof arg === 'object' && 'kind' in arg && (arg as NavigatableWidgetOptions).kind === 'navigatable';
+        return isObject(arg) && arg.kind === 'navigatable';
     }
 }

packages/core/src/browser/preferences/injectable-preference-proxy.ts

@@ -16,7 +16,7 @@
 
 import { inject, injectable, postConstruct } from 'inversify';
 import { PreferenceSchema } from '../../common/preferences/preference-schema';
-import { Disposable, DisposableCollection, Emitter, Event, MaybePromise } from '../../common';
+import { Disposable, DisposableCollection, Emitter, Event, isObject, MaybePromise } from '../../common';
 import { PreferenceChangeEvent, PreferenceEventEmitter, PreferenceProxy, PreferenceProxyOptions, PreferenceRetrieval } from './preference-proxy';
 import { PreferenceChange, PreferenceChangeImpl, PreferenceChanges, PreferenceScope, PreferenceService } from './preference-service';
 import { JSONValue } from '@phosphor/coreutils';
@@ -103,7 +103,9 @@ export class InjectablePreferenceProxy<T extends Record<string, JSONValue>> impl
     }
 
     get(target: unknown, property: string, receiver: unknown): unknown {
-        if (typeof property !== 'string') { throw new Error(`Unexpected property: ${String(property)}`); }
+        if (typeof property !== 'string') {
+            throw new Error(`Unexpected property: ${String(property)}`);
+        }
         const preferenceName = this.prefix + property;
         if (this.schema && (this.isFlat || !property.includes('.')) && this.schema.properties[preferenceName]) {
             const { overrideIdentifier } = this;
@@ -143,7 +145,7 @@ export class InjectablePreferenceProxy<T extends Record<string, JSONValue>> impl
             } while (parentSegment && value === undefined);
 
             let segment;
-            while (typeof value === 'object' && (segment = segments.pop())) {
+            while (isObject(value) && (segment = segments.pop())) {
                 value = value[segment];
             }
             return segments.length ? undefined : value;

packages/core/src/browser/preferences/preference-contribution.ts

@@ -26,7 +26,7 @@ import { FrontendApplicationConfigProvider } from '../frontend-application-confi
 import { FrontendApplicationConfig } from '@theia/application-package/lib/application-props';
 import { bindPreferenceConfigurations, PreferenceConfigurations } from './preference-configurations';
 export { PreferenceSchema, PreferenceSchemaProperties, PreferenceDataSchema, PreferenceItem, PreferenceSchemaProperty, PreferenceDataProperty };
-import { Mutable } from '../../common/types';
+import { isObject, Mutable } from '../../common/types';
 import { PreferenceLanguageOverrideService } from './preference-language-override-service';
 import { JSONValue } from '@phosphor/coreutils';
 
@@ -80,7 +80,7 @@ export interface FrontendApplicationPreferenceConfig extends FrontendApplication
 }
 export namespace FrontendApplicationPreferenceConfig {
     export function is(config: FrontendApplicationConfig): config is FrontendApplicationPreferenceConfig {
-        return 'preferences' in config && typeof config['preferences'] === 'object';
+        return isObject(config.preferences);
     }
 }
 

packages/core/src/browser/preferences/preference-language-override-service.ts

@@ -15,7 +15,7 @@
 // *****************************************************************************
 
 import { injectable } from 'inversify';
-import { escapeRegExpCharacters } from '../../common';
+import { escapeRegExpCharacters, isObject } from '../../common';
 import { PreferenceSchemaProperties } from '../../common/preferences/preference-schema';
 
 export interface OverridePreferenceName {
@@ -24,7 +24,7 @@ export interface OverridePreferenceName {
 }
 export namespace OverridePreferenceName {
     export function is(arg: unknown): arg is OverridePreferenceName {
-        return !!arg && typeof arg === 'object' && 'preferenceName' in arg && 'overrideIdentifier' in arg;
+        return isObject(arg) && 'preferenceName' in arg && 'overrideIdentifier' in arg;
     }
 }
 

packages/core/src/browser/preferences/preference-provider.ts

@@ -20,7 +20,7 @@ import debounce = require('p-debounce');
 import { injectable, inject } from 'inversify';
 import { JSONExt, JSONValue } from '@phosphor/coreutils';
 import URI from '../../common/uri';
-import { Disposable, DisposableCollection, Emitter, Event } from '../../common';
+import { Disposable, DisposableCollection, Emitter, Event, isObject } from '../../common';
 import { Deferred } from '../../common/promise-util';
 import { PreferenceScope } from './preference-scope';
 import { PreferenceLanguageOverrideService } from './preference-language-override-service';
@@ -253,16 +253,12 @@ export abstract class PreferenceProvider implements Disposable {
 
     protected getParsedContent(jsonData: any): { [key: string]: any } {
         const preferences: { [key: string]: any } = {};
-        if (typeof jsonData !== 'object') {
+        if (!isObject(jsonData)) {
             return preferences;
         }
-        // eslint-disable-next-line guard-for-in
-        for (const preferenceName in jsonData) {
-            const preferenceValue = jsonData[preferenceName];
+        for (const [preferenceName, preferenceValue] of Object.entries(jsonData)) {
             if (this.preferenceOverrideService.testOverrideValue(preferenceName, preferenceValue)) {
-                // eslint-disable-next-line guard-for-in
-                for (const overriddenPreferenceName in preferenceValue) {
-                    const overriddenValue = preferenceValue[overriddenPreferenceName];
+                for (const [overriddenPreferenceName, overriddenValue] of Object.entries(preferenceValue)) {
                     preferences[`${preferenceName}.${overriddenPreferenceName}`] = overriddenValue;
                 }
             } else {

packages/core/src/browser/preferences/preference-proxy.ts

@@ -16,7 +16,7 @@
 
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-import { Disposable, Event, MaybePromise } from '../../common';
+import { Disposable, Event, isObject, MaybePromise } from '../../common';
 import { PreferenceService } from './preference-service';
 import { PreferenceSchema } from './preference-contribution';
 import { PreferenceScope } from './preference-scope';
@@ -332,7 +332,7 @@ export function createPreferenceProxy<T>(preferences: PreferenceService, promise
             } while (parentSegment && value === undefined);
 
             let segment;
-            while (typeof value === 'object' && (segment = segments.pop())) {
+            while (isObject(value) && (segment = segments.pop())) {
                 value = value[segment];
             }
             return segments.length ? undefined : value;

packages/core/src/browser/saveable.ts

@@ -22,6 +22,7 @@ import { Key } from './keyboard/keys';
 import { AbstractDialog } from './dialogs';
 import { waitForClosed } from './widgets';
 import { nls } from '../common/nls';
+import { isObject } from '../common';
 
 export interface Saveable {
     readonly dirty: boolean;
@@ -60,10 +61,10 @@ export namespace Saveable {
 
     export type Snapshot = { value: string } | { read(): string | null };
     export function isSource(arg: unknown): arg is SaveableSource {
-        return typeof arg === 'object' && !!arg && is((arg as SaveableSource).saveable);
+        return isObject<SaveableSource>(arg) && is(arg.saveable);
     }
     export function is(arg: unknown): arg is Saveable {
-        return typeof arg === 'object' && !!arg && 'dirty' in arg && 'onDirtyChanged' in arg;
+        return isObject(arg) && 'dirty' in arg && 'onDirtyChanged' in arg;
     }
     export function get(arg: unknown): Saveable | undefined {
         if (is(arg)) {

packages/core/src/browser/shell/application-shell.ts

@@ -22,7 +22,7 @@ import {
 } from '@phosphor/widgets';
 import { Message } from '@phosphor/messaging';
 import { IDragEvent } from '@phosphor/dragdrop';
-import { RecursivePartial, Event as CommonEvent, DisposableCollection, Disposable, environment } from '../../common';
+import { RecursivePartial, Event as CommonEvent, DisposableCollection, Disposable, environment, isObject } from '../../common';
 import { animationFrame } from '../browser';
 import { Saveable, SaveableWidget, SaveOptions, SaveableSource } from '../saveable';
 import { StatusBarImpl, StatusBarEntry, StatusBarAlignment } from '../status-bar/status-bar';
@@ -2108,7 +2108,7 @@ export namespace ApplicationShell {
 
     export namespace TrackableWidgetProvider {
         export function is(widget: unknown): widget is TrackableWidgetProvider {
-            return !!widget && typeof widget === 'object' && 'getTrackableWidgets' in widget;
+            return isObject(widget) && 'getTrackableWidgets' in widget;
         }
     }
 

packages/core/src/browser/shell/shell-layout-restorer.ts

@@ -23,11 +23,11 @@ import { ILogger } from '../../common/logger';
 import { CommandContribution, CommandRegistry, Command } from '../../common/command';
 import { ThemeService } from '../theming';
 import { ContributionProvider } from '../../common/contribution-provider';
-import { MaybePromise } from '../../common/types';
 import { ApplicationShell, applicationShellLayoutVersion, ApplicationShellLayoutVersion } from './application-shell';
 import { CommonCommands } from '../common-frontend-contribution';
 import { WindowService } from '../window/window-service';
 import { StopReason } from '../../common/frontend-application-state';
+import { isFunction, isObject, MaybePromise } from '../../common';
 
 /**
  * A contract for widgets that want to store and restore their inner state, between sessions.
@@ -47,7 +47,7 @@ export interface StatefulWidget {
 
 export namespace StatefulWidget {
     export function is(arg: unknown): arg is StatefulWidget {
-        return !!arg && typeof arg === 'object' && typeof (arg as StatefulWidget).storeState === 'function' && typeof (arg as StatefulWidget).restoreState === 'function';
+        return isObject<StatefulWidget>(arg) && isFunction(arg.storeState) && isFunction(arg.restoreState);
     }
 }
 
@@ -232,11 +232,7 @@ export class ShellLayoutRestorer implements CommandContribution {
         const parseContext = new ShellLayoutRestorer.ParseContext();
         const layout = this.parse<ApplicationShell.LayoutData>(layoutData, parseContext);
 
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        let layoutVersion: number | any;
-        try {
-            layoutVersion = 'version' in layout && Number(layout.version);
-        } catch { /* no-op */ }
+        const layoutVersion = Number(layout.version);
         if (typeof layoutVersion !== 'number' || Number.isNaN(layoutVersion)) {
             throw new Error('could not resolve a layout version');
         }
@@ -282,9 +278,8 @@ export class ShellLayoutRestorer implements CommandContribution {
                     });
                 }
                 return widgets;
-            } else if (value && typeof value === 'object' && !Array.isArray(value)) {
-                // eslint-disable-next-line @typescript-eslint/no-explicit-any
-                const copy: any = {};
+            } else if (isObject<Record<string, WidgetDescription>>(value) && !Array.isArray(value)) {
+                const copy: Record<string, unknown> = {};
                 for (const p in value) {
                     if (this.isWidgetProperty(p)) {
                         parseContext.push(async context => {
@@ -306,7 +301,7 @@ export class ShellLayoutRestorer implements CommandContribution {
                 // don't catch exceptions, if one migration fails all should fail.
                 const migrated = await migration.onWillInflateWidget(desc, context);
                 if (migrated) {
-                    if (migrated.innerWidgetState && typeof migrated.innerWidgetState !== 'string') {
+                    if (isObject(migrated.innerWidgetState)) {
                         // in order to inflate nested widgets
                         migrated.innerWidgetState = JSON.stringify(migrated.innerWidgetState);
                     }

packages/core/src/browser/shell/tab-bar-toolbar/tab-bar-toolbar-types.ts

@@ -15,7 +15,7 @@
 // *****************************************************************************
 
 import * as React from 'react';
-import { ArrayUtils, Event, MenuPath } from '../../../common';
+import { ArrayUtils, Event, isFunction, isObject, isString, MenuPath } from '../../../common';
 import { Widget } from '../../widgets';
 
 /** Items whose group is exactly 'navigation' will be rendered inline. */
@@ -27,13 +27,9 @@ export interface TabBarDelegator extends Widget {
 }
 
 export namespace TabBarDelegator {
-    export const is = (candidate?: Widget): candidate is TabBarDelegator => {
-        if (candidate) {
-            const asDelegator = candidate as TabBarDelegator;
-            return typeof asDelegator.getTabBarDelegate === 'function';
-        }
-        return false;
-    };
+    export function is(candidate?: Widget): candidate is TabBarDelegator {
+        return isObject<TabBarDelegator>(candidate) && isFunction(candidate.getTabBarDelegate);
+    }
 }
 
 interface RegisteredToolbarItem {
@@ -172,14 +168,13 @@ export namespace TabBarToolbarItem {
     };
 
     export function is(arg: unknown): arg is TabBarToolbarItem {
-        return !!arg && typeof arg === 'object' && 'command' in arg && typeof (arg as TabBarToolbarItem).command === 'string';
+        return isObject<TabBarToolbarItem>(arg) && isString(arg.command);
     }
 
 }
 
 export namespace MenuToolbarItem {
     export function getMenuPath(item: AnyToolbarItem): MenuPath | undefined {
-        const asDelegate = item as MenuToolbarItem;
-        return Array.isArray(asDelegate.menuPath) ? asDelegate.menuPath : undefined;
+        return Array.isArray(item.menuPath) ? item.menuPath : undefined;
     }
 }

packages/core/src/browser/shell/tab-bar-toolbar/tab-bar-toolbar.tsx

@@ -109,7 +109,7 @@ export class TabBarToolbar extends ReactWidget {
         const classNames = [];
         if (item.text) {
             for (const labelPart of this.labelParser.parse(item.text)) {
-                if (typeof labelPart !== 'string' && LabelIcon.is(labelPart)) {
+                if (LabelIcon.is(labelPart)) {
                     const className = `fa fa-${labelPart.name}${labelPart.animation ? ' fa-' + labelPart.animation : ''}`;
                     classNames.push(...className.split(' '));
                 } else {

packages/core/src/browser/source-tree/tree-source.ts

@@ -18,9 +18,7 @@
 
 import { ReactNode } from 'react';
 import { injectable, unmanaged } from 'inversify';
-import { Emitter, Event } from '../../common/event';
-import { MaybePromise } from '../../common/types';
-import { Disposable, DisposableCollection } from '../../common/disposable';
+import { Disposable, DisposableCollection, Emitter, Event, isObject, MaybePromise } from '../../common';
 import { TreeWidget } from '../tree';
 
 export interface TreeElement {
@@ -39,7 +37,7 @@ export interface CompositeTreeElement extends TreeElement {
 }
 export namespace CompositeTreeElement {
     export function is(element: unknown): element is CompositeTreeElement {
-        return !!element && typeof element === 'object' && 'getElements' in element;
+        return isObject(element) && 'getElements' in element;
     }
     export function hasElements(element: unknown): element is CompositeTreeElement {
         return is(element) && element.hasElements !== false;

packages/core/src/browser/status-bar/status-bar.tsx

@@ -165,7 +165,7 @@ export class StatusBarImpl extends ReactWidget implements StatusBar {
         const children: JSX.Element[] = [];
 
         childStrings.forEach((val, key) => {
-            if (!(typeof val === 'string') && LabelIcon.is(val)) {
+            if (LabelIcon.is(val)) {
                 const animation = val.animation ? ` fa-${val.animation}` : '';
                 if (val.name.startsWith('codicon-')) {
                     children.push(<span key={key} className={`codicon ${val.name}${animation}`}></span>);