Fix bugs found in E2E testing

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')
     }