reorganize upload code in prep for merge logic, add more tests

src/upload/constants.ts

@@ -0,0 +1,26 @@
+/* eslint-disable no-unused-vars */
+export enum Inputs {
+  Name = 'name',
+  Path = 'path',
+  IfNoFilesFound = 'if-no-files-found',
+  RetentionDays = 'retention-days',
+  CompressionLevel = 'compression-level',
+  Overwrite = 'overwrite'
+}
+
+export enum NoFileOptions {
+  /**
+   * Default. Output a warning but do not fail the action
+   */
+  warn = 'warn',
+
+  /**
+   * Fail the action with an error message
+   */
+  error = 'error',
+
+  /**
+   * Do not output any warnings or errors, the action does not fail
+   */
+  ignore = 'ignore'
+}