Add PowerShell package (#1783)

Signed-off-by: Chris Hunt <114173+cdhunt@users.noreply.github.com>

pkg/universe.dagger.io/powershell/powershell.cue

@@ -0,0 +1,54 @@
+// Helpers to run PowerShell commands in containers
+package powershell
+
+import (
+	"dagger.io/dagger"
+	"universe.dagger.io/docker"
+)
+
+// Run a PowerShell (pwsh) script in a Docker container
+//  This does not suppore Windows containers or Windows PowerShell.
+//  Since this is a thin wrapper over docker.#Run, we embed it.
+//  Whether to embed or wrap is a case-by-case decision, like in Go.
+#Run: {
+	// The script to execute
+	script: {
+		// A directory containing one or more PowerShell scripts
+		directory: dagger.#FS
+
+		// Name of the file to execute
+		filename: string
+
+		_directory: directory
+		_filename:  filename
+	} | {
+		// Script contents
+		contents: string
+
+		_filename: "run.ps1"
+		_write:    dagger.#WriteFile & {
+			input:      dagger.#Scratch
+			path:       _filename
+			"contents": contents
+		}
+		_directory: _write.output
+	}
+
+	// Arguments to the script
+	args: [...string]
+
+	// Where in the container to mount the scripts directory
+	_mountpoint: "/powershell/scripts"
+
+	docker.#Run & {
+		command: {
+			name:   "pwsh"
+			"args": args
+			flags: "-File": "\(_mountpoint)/\(script._filename)"
+		}
+		mounts: "Pwsh scripts": {
+			contents: script._directory
+			dest:     _mountpoint
+		}
+	}
+}

pkg/universe.dagger.io/powershell/test/data/hello.ps1

@@ -0,0 +1 @@
+Set-Content -Value "Hello world!" -Path "/out.txt"

pkg/universe.dagger.io/powershell/test/test.bats

@@ -0,0 +1,10 @@
+setup() {
+    load '../../bats_helpers'
+
+    common_setup
+}
+
+@test "powershell" {
+    dagger "do" -p ./test.cue test
+}
+

pkg/universe.dagger.io/powershell/test/test.cue

@@ -0,0 +1,71 @@
+package powershell
+
+import (
+	"dagger.io/dagger"
+
+	"universe.dagger.io/docker"
+	"universe.dagger.io/powershell"
+)
+
+dagger.#Plan & {
+	actions: test: {
+
+		_pull: docker.#Pull & {
+			source: "mcr.microsoft.com/powershell"
+		}
+		_image: _pull.output
+
+		// Run a script from source directory + filename
+		runFile: {
+
+			dir:   _load.output
+			_load: dagger.#Source & {
+				path: "./data"
+				include: ["*.ps1"]
+			}
+
+			run: powershell.#Run & {
+				input: _image
+				export: files: "/out.txt": _
+				script: {
+					directory: dir
+					filename:  "hello.ps1"
+				}
+			}
+			output: run.export.files."/out.txt" & "Hello world!\n"
+		}
+
+		// Run a script from string
+		runString: {
+			run: powershell.#Run & {
+				input: _image
+				export: files: "/output.txt": _
+				script: contents: "Set-Content -Value 'Hello inline world!' -Path '/output.txt'"
+			}
+			output: run.export.files."/output.txt" & "Hello inline world!\n"
+		}
+
+		// Test args from string
+		runStringArg: {
+			run: powershell.#Run & {
+				input: _image
+				export: files: "/output.txt": _
+				script: contents: "Set-Content -Value 'Hello arg world!' -Path $($args[0])"
+				args: ["/output.txt"]
+			}
+			output: run.export.files."/output.txt" & "Hello arg world!\n"
+		}
+
+		// Test 2 args from string
+		runString2Arg: {
+			run: powershell.#Run & {
+				input: _image
+				export: files: "/output.txt": _
+				script: contents: "Set-Content -Value \"Hello args $($args[0])\" -Path $($args[1])"
+				args: ["world!", "/output.txt"]
+			}
+			output: run.export.files."/output.txt" & "Hello args world!\n"
+		}
+
+	}
+}