Added typings for package

package.json

@@ -27,13 +27,16 @@
     "url": "https://github.com/apla/node-clickhouse/issues"
   },
   "homepage": "https://github.com/apla/node-clickhouse#readme",
-  "dependencies": {},
+  "dependencies": {
+    "@types/node": "*"
+  },
   "devDependencies": {
     "bluebird": "^3.5.0",
     "codecov": "^2.2.0",
     "mocha": "^2.5.3",
     "nyc": "^10.2.0"
   },
+  "typings": "typings.d.ts",
   "engines": {
     "node": ">=0.10"
   }

typings.d.ts

@@ -0,0 +1,87 @@
+/// <reference types="node" />
+import * as https from "https";
+import * as stream from "stream";
+
+declare class ClickHouse<ConstructorOptions extends ClickHouse.Options = ClickHouse.Options> {
+    constructor(options: ConstructorOptions);
+    query(chQuery: string, options: ClickHouse.QueryOptions, cb?: ClickHouse.QueryCallback): ClickHouse.RecordStream;
+    query(chQuery: string, cb?: ClickHouse.QueryCallback): ClickHouse.RecordStream;
+    querying<
+        QueryOptions extends ClickHouse.QueryOptions,
+        RecordType extends ClickHouse.DefaultRecordType<ConstructorOptions, QueryOptions, unknown> = ClickHouse.DefaultRecordType<ConstructorOptions, QueryOptions, any>
+    >(chQuery: string, options?: QueryOptions): Promise<ClickHouse.QueryResult<RecordType>>;
+    ping(cb?: ClickHouse.QueryCallback): ClickHouse.RecordStream;
+    pinging(): Promise<string>;
+}
+
+declare namespace ClickHouse {
+    type SpecificConstructorOptions = {
+        // Host is required, overriding it
+        host: string;
+        user?: string;
+        password?: string;
+        useQueryString?: boolean;
+    } & QueryOptions;
+
+    type ConstructorOptions = https.RequestOptions & SpecificConstructorOptions;
+
+    export type Options = ConstructorOptions | string;
+
+    export type QueryOptions = {
+        dataObjects?: boolean;
+        format?: Format;
+        syncParser?: boolean;
+        omitFormat?: boolean;
+        readonly?: boolean;
+        queryOptions?: {
+            [key: string]: string | number | boolean;
+        };
+    };
+
+    export type QueryCallback = (error?: Error) => void;
+
+    export class RecordStream extends stream.Duplex {}
+
+    export type Format = "TabSeparated" | "TSV" | "TabSeparatedRaw" | "TSVRaw" | "TabSeparatedWithNames" | "TSVWithNames" | "TabSeparatedWithNamesAndTypes" | "TSVWithNamesAndTypes" | "Template" | "TemplateIgnoreSpaces" | "CSV" | "CSVWithNames" | "CustomSeparated" | "Values" | "Vertical" | "JSON" | "JSONCompact" | "JSONEachRow" | "TSKV" | "Pretty" | "PrettyCompact" | "PrettyCompactMonoBlock" | "PrettyNoEscapes" | "PrettySpace" | "Protobuf" | "Parquet" | "RowBinary" | "RowBinaryWithNamesAndTypes" | "Native" | "Null" | "XML" | "CapnProto";
+
+    type StringResultFormat = Exclude<Format, "JSON" | "JSONCompact">;
+
+    // This is returned when format=JSON, format=JSONCompact or dataObject=true specified
+    export type ObjectQueryResult<RecordType> = {
+        meta: Array<{
+            name: string;
+            type: string;
+        }>;
+        totals?: any;
+        extremes?: any;
+        data: Array<RecordType>;
+        rows: number;
+        rows_before_limit_at_least?: number;
+        statistics: {
+            elapsed: number;
+            rows_read: number;
+            bytes_read: number;
+        };
+        transferred: number;
+    }
+
+    // DefaultRecordType<ConstructorOptions, QueryOptions, unknown> is used to check any user-defined type
+    // DefaultRecordType<ConstructorOptions, QueryOptions, any> is used as a default if user does not supply specific type
+    // DefaultRecordType<ConstructorOptions, QueryOptions, any> cannot be used to check user-defined type as it allows pretty much anything, including Array
+    type DefaultRecordType<ConstructorOptions, QueryOptions, Value> =
+        QueryOptions extends {format: "JSON"} ? Record<string, Value> :
+        QueryOptions extends {format: "JSONCompact"} ? Array<Value> :
+        QueryOptions extends {format: StringResultFormat} ? null :
+        ConstructorOptions extends {format: "JSON"} ? Record<string, Value> :
+        ConstructorOptions extends {format: "JSONCompact"} ? Array<Value> :
+        ConstructorOptions extends {format: StringResultFormat} ? null :
+        QueryOptions extends {dataObjects: true} ? Record<string, Value> :
+        ConstructorOptions extends {dataObjects: true} ? Record<string, Value> :
+        Array<Value>;
+
+    // string is returned for any non-JSON format
+    export type QueryResult<RecordType> =
+        RecordType extends null ? string : ObjectQueryResult<RecordType>;
+}
+
+export = ClickHouse;