feat: support downloading multiple artifacts to different paths

There is a few use cases where we want to download a few different artifacts but
not all of them. This commit implements this support, without breaking backward
compatibility. Two build test cases were also added to the pipeline.

.github/workflows/test.yml

@@ -89,7 +89,56 @@ jobs:
         }
       shell: pwsh
 
-    # Test downloading both artifacts at once
+    # Test downloading multiple artifacts to the same path
+    - name: Download artifacts A and B to the same path
+      uses: ./
+      with:
+        name: |
+          Artifact-A
+          Artifact-B
+        path: some/path/for/multiple/files
+
+    - name: Verify successful download
+      run: |
+        $fileA = "some/path/for/multiple/files/file-A.txt"
+        $fileB = "some/path/for/multiple/files/file-B.txt"
+        if(!(Test-Path -path $fileA) -or !(Test-Path -path $fileB))
+        {
+            Write-Error "Expected files do not exist"
+        }
+        if(!((Get-Content $fileA) -ceq "Lorem ipsum dolor sit amet") -or !((Get-Content $fileB) -ceq "Hello world from file B"))
+        {
+            Write-Error "File contents of downloaded artifacts are incorrect"
+        }
+      shell: pwsh
+
+    # Test downloading multiple artifacts to different paths
+    - name: Download artifacts A and B to different paths
+      uses: ./
+      with:
+        name: |
+          Artifact-A
+          Artifact-B
+        path: |
+          some/path/for/a
+          some/path/for/b
+
+
+    - name: Verify successful download
+      run: |
+        $fileA = "some/path/for/a/file-A.txt"
+        $fileB = "some/path/for/b/file-B.txt"
+        if(!(Test-Path -path $fileA) -or !(Test-Path -path $fileB))
+        {
+            Write-Error "Expected files do not exist"
+        }
+        if(!((Get-Content $fileA) -ceq "Lorem ipsum dolor sit amet") -or !((Get-Content $fileB) -ceq "Hello world from file B"))
+        {
+            Write-Error "File contents of downloaded artifacts are incorrect"
+        }
+      shell: pwsh
+
+    # Test downloading all artifacts
     - name: Download all Artifacts
       uses: ./
       with:
@@ -108,5 +157,3 @@ jobs:
             Write-Error "File contents of downloaded artifacts are incorrect"
         }
       shell: pwsh
-
-      

src/constants.ts

@@ -1,7 +1,7 @@
 export enum Inputs {
-  Name = 'name',
-  Path = 'path'
+  Names = 'name',
+  Paths = 'path'
 }
 export enum Outputs {
-  DownloadPath = 'download-path'
+  DownloadPaths = 'download-path'
 }

src/download-artifact.ts

@@ -4,11 +4,7 @@ import * as os from 'os'
 import {resolve} from 'path'
 import {Inputs, Outputs} from './constants'
 
-async function run(): Promise<void> {
-  try {
-    const name = core.getInput(Inputs.Name, {required: false})
-    const path = core.getInput(Inputs.Path, {required: false})
-
+async function downloadArtifact(name: string, path: string): Promise<string> {
   let resolvedPath
   // resolve tilde expansions, path.replace only replaces the first occurrence of a pattern
   if (path.startsWith(`~`)) {
@@ -51,8 +47,75 @@ async function run(): Promise<void> {
   }
   // output the directory that the artifact(s) was/were downloaded to
   // if no path is provided, an empty string resolves to the current working directory
-    core.setOutput(Outputs.DownloadPath, resolvedPath)
   core.info('Artifact download has finished successfully')
+
+  return resolvedPath
+}
+
+async function run(): Promise<void> {
+  try {
+    const names = core.getMultilineInput(Inputs.Names, {required: false})
+    const paths = core.getMultilineInput(Inputs.Paths, {required: false})
+
+    core.info(`names: '${JSON.stringify(names)}' | length: ${names.length}`)
+    core.info(`paths: '${JSON.stringify(paths)}' | length: ${paths.length}`)
+
+    let downloadPaths: string[] = []
+
+    // Names is set and has fewer entries than Paths
+    if (names.length !== 0 && paths.length > names.length) {
+      throw Error(
+        `The input 'path' cannot have more entries than 'name', if 'name' is set.`
+      )
+    }
+    // Names is NOT set and Paths has more than 1 entry
+    else if (names.length === 0 && paths.length > 1) {
+      throw Error(
+        `The input 'path' cannot have more than one entry, if 'name' is not set.`
+      )
+    }
+    // Names is NOT set and path has at max 1 entry: download all artifacts
+    else if (names.length === 0 && paths.length <= 1) {
+      const name = names.toString() // ''
+      const path = paths.toString() // '' or 'some/path'
+      const downloadPath = await downloadArtifact(name, path)
+      downloadPaths.push(downloadPath)
+    }
+    // Names has one or more entries and Paths has at max 1 entry
+    else if (names.length >= 1 && paths.length <= 1) {
+      const path = paths.toString() // '' or 'some/path'
+      names.forEach(async name => {
+        const downloadPath = await downloadArtifact(name, path)
+        downloadPaths.push(downloadPath)
+      })
+    }
+    // Names and Paths have the same numbers of entries (more than 1)
+    else if (
+      names.length > 1 &&
+      paths.length > 1 &&
+      names.length === paths.length
+    ) {
+      names.forEach(async (name, index) => {
+        const path = paths[index]
+        const downloadPath = await downloadArtifact(name, path)
+        downloadPaths.push(downloadPath)
+      })
+    }
+    // Unhandled exception
+    else {
+      throw Error(
+        `Unhandled scenario. This shouldn't happen. It's very likely a bug. :-()`
+      )
+    }
+
+    // Remove duplicates and empty strings
+    downloadPaths = [...new Set(downloadPaths.filter(path => path !== ''))]
+
+    // Returns a newline-separated list of paths
+    const output = downloadPaths.join('\n')
+
+    // output the directory that the artifact(s) was/were downloaded to
+    core.setOutput(Outputs.DownloadPaths, output)
   } catch (err) {
     core.setFailed(err.message)
   }