[TS] Make strict compliant and improve typings (#7549)

* [TS] Make strict compliant and improve typings

* clang-format

* Code gen harmonize

Co-authored-by: Derek Bailey <derekbailey@google.com>

ts/builder.ts

@@ -549,7 +549,7 @@ export class Builder {
      * 
      * @returns offset of obj
      */
-    createObjectOffset(obj: string | any): Offset {
+    createObjectOffset(obj: string | IGeneratedObject | null): Offset {
       if(obj === null) {
         return 0
       }
@@ -566,7 +566,7 @@ export class Builder {
      * 
      * @returns list of offsets of each non null object
      */
-    createObjectOffsetList(list: string[] | any[]): Offset[] {
+    createObjectOffsetList(list: (string | IGeneratedObject)[]): Offset[] {
       const ret: number[] = [];
   
       for(let i = 0; i < list.length; ++i) {
@@ -583,7 +583,7 @@ export class Builder {
       return ret;
     }
   
-    createStructOffsetList(list: string[] | any[], startFunc: (builder: Builder, length: number) => void): Offset {
+    createStructOffsetList(list: (string | IGeneratedObject)[], startFunc: (builder: Builder, length: number) => void): Offset {
       startFunc(this, list.length);
       this.createObjectOffsetList(list.slice().reverse());
       return this.endVector();

ts/byte-buffer.ts

@@ -1,6 +1,6 @@
 import { FILE_IDENTIFIER_LENGTH, SIZEOF_INT } from "./constants.js";
 import { int32, isLittleEndian, float32, float64 } from "./utils.js";
-import { Offset, Table, IGeneratedObject } from "./types.js";
+import { Offset, Table, IGeneratedObject, IUnpackableObject } from "./types.js";
 import { Encoding } from "./encoding.js";
 
 export class ByteBuffer {
@@ -257,33 +257,31 @@ export class ByteBuffer {
     /**
      * A helper function for generating list for obj api
      */
-    createScalarList(listAccessor: (i: number) => unknown, listLength: number): any[] {
-      const ret: any[]  = [];
+    createScalarList<T>(listAccessor: (i: number) => T | null, listLength: number): T[] {
+      const ret: T[]  = [];
       for(let i = 0; i < listLength; ++i) {
-        if(listAccessor(i) !== null) {
-          ret.push(listAccessor(i));
+        const val = listAccessor(i);
+        if(val !== null) {
+          ret.push(val);
         }
       }
-  
       return ret;
     }
-  
+
     /**
      * A helper function for generating list for obj api
      * @param listAccessor function that accepts an index and return data at that index
      * @param listLength listLength
      * @param res result list
      */
-    createObjList(listAccessor: (i: number) => unknown, listLength: number): any[] {
-      const ret: any[] = [];
+    createObjList<T1 extends IUnpackableObject<T2>, T2 extends IGeneratedObject>(listAccessor: (i: number) => T1 | null, listLength: number): T2[] {
+      const ret: T2[] = [];
       for(let i = 0; i < listLength; ++i) {
         const val = listAccessor(i);
         if(val !== null) {
-          ret.push((val as IGeneratedObject).unpack());
+          ret.push(val.unpack());
         }
       }
-      
       return ret;
     }
-  
   }

ts/flatbuffers.ts

@@ -0,0 +1 @@
+export * as flatbuffers from './index.js'

ts/index.ts

@@ -3,7 +3,7 @@ export { SIZEOF_INT } from './constants.js'
 export { FILE_IDENTIFIER_LENGTH } from './constants.js'
 export { SIZE_PREFIX_LENGTH } from './constants.js'
 
-export { Table, Offset } from './types.js'
+export { Table, Offset, IGeneratedObject, IUnpackableObject } from './types.js'
 
 export { int32, float32, float64, isLittleEndian } from './utils.js'
 

ts/types.ts

@@ -10,5 +10,8 @@ export type Table = {
 
 export interface IGeneratedObject {
   pack(builder:Builder): Offset
-  unpack(): IGeneratedObject
+}
+
+export interface IUnpackableObject<T> {
+  unpack(): T
 }