Fix bugs found in E2E testing

src/Action.ts

@@ -1,6 +1,7 @@
 import { Inputs } from "./Inputs";
 import { Releases } from "./Releases";
 import { basename } from "path";
+import { readFileSync } from "fs";
 
 export class Action {
     private inputs: Inputs
@@ -21,12 +22,13 @@ export class Action {
         )
 
         if (this.inputs.artifact) {
+            const artifactData = this.inputs.readArtifact()
             await this.releases.uploadArtifact(
-                createResult.data.assets_url,
+                createResult.data.upload_url,
                 this.inputs.artifactContentLength,
                 this.inputs.artifactContentType,
-                this.inputs.artifact,
-                basename(this.inputs.artifact)
+                artifactData,
+                this.inputs.artifactName
             )
         }
     }

src/Inputs.ts

@@ -1,9 +1,11 @@
 import * as core from '@actions/core';
 import { Context } from "@actions/github/lib/context";
 import { readFileSync, statSync } from 'fs';
+import { basename } from 'path';
 
 export interface Inputs {
     readonly artifact: string
+    readonly artifactName: string
     readonly artifactContentType: string
     readonly artifactContentLength: number
     readonly body: string
@@ -12,6 +14,8 @@ export interface Inputs {
     readonly name: string
     readonly tag: string
     readonly token: string
+
+    readArtifact(): Buffer
 }
 
 export class CoreInputs implements Inputs {
@@ -25,6 +29,10 @@ export class CoreInputs implements Inputs {
         return core.getInput('artifact')
     }
 
+    get artifactName(): string {
+        return basename(this.artifact)
+    }
+
     get artifactContentType(): string {
         const type = core.getInput('artifactContentType')
         if(type) {
@@ -89,6 +97,10 @@ export class CoreInputs implements Inputs {
         return core.getInput('token', { required: true })
     }
 
+    readArtifact(): Buffer {
+        return readFileSync(this.artifact)
+    }
+
     stringFromFile(path: string): string {
         return readFileSync(path, 'utf-8')
     }

src/Releases.ts

@@ -15,7 +15,7 @@ export interface Releases {
         assetUrl: string,
         contentLength: number,
         contentType: string,
-        file: string,
+        file: string | object,
         name: string
     ): Promise<Response<AnyResponse>>
 }
@@ -51,7 +51,7 @@ export class GithubReleases implements Releases{
         assetUrl: string,
         contentLength: number,
         contentType: string,
-        file: string,
+        file: string | object,
         name: string
     ): Promise<Response<AnyResponse>> {
         return this.git.repos.uploadReleaseAsset({