add support for using a shell to run commands

packages/exec/__tests__/exec.test.ts

@@ -153,6 +153,23 @@ describe('@actions/exec', () => {
     expect(output.trim()).toBe(`hello`)
   })
 
+  it('Runs exec successfully with shell wildcard substitution', async () => {
+    let tool: string
+    let args: string[]
+    let opts: im.ExecOptions
+    if (IS_WINDOWS) {
+      tool = 'cmd'
+      args = ['/c', 'echo', 'hello']
+      opts = {shell: process.env.ComSpec}
+    } else {
+      tool = 'ls'
+      args = ['-l', '*.md']
+      opts = {shell: '/bin/sh'}
+    }
+    const exitCode = await exec.exec(tool, args, opts)
+    expect(exitCode).toBe(0)
+  })
+
   it('Exec fails with error on bad call', async () => {
     const _testExecOptions = getExecOptions()
 

packages/exec/src/interfaces.ts

@@ -12,6 +12,9 @@ export interface ExecOptions {
   /** optional.  defaults to false */
   silent?: boolean
 
+  /** optional. Runs command inside of a shell. A different shell can be specified as a string. Defaults to false */
+  shell?: boolean | string
+
   /** optional out stream to use. Defaults to process.stdout */
   outStream?: stream.Writable
 

packages/exec/src/toolrunner.ts

@@ -377,6 +377,7 @@ export class ToolRunner extends events.EventEmitter {
     const result = <child.SpawnOptions>{}
     result.cwd = options.cwd
     result.env = options.env
+    result.shell = options.shell
     result['windowsVerbatimArguments'] =
       options.windowsVerbatimArguments || this._isCmdFile()
     if (options.windowsVerbatimArguments) {