Add outputs.files task to plan

Signed-off-by: Helder Correia <174525+helderco@users.noreply.github.com>

pkg/dagger.io/dagger/engine/plan.cue

@@ -17,8 +17,10 @@ package engine
 
 	// Send outputs to the client
 	outputs: {
-		@dagger(notimplemented)
+		// Export an #FS to the client
 		directories: [name=string]: _#outputDirectory
+		// Export a string to a file
+		files: [name=string]: _#outputFile
 	}
 
 	// Forward network services to and from the client
@@ -110,6 +112,19 @@ _#outputDirectory: {
 	dest: string
 }
 
+_#outputFile: {
+	$dagger: task: _name: "OutputFile"
+
+	// File contents to export
+	contents: string
+
+	// Export to this path ON THE CLIENT MACHINE
+	dest: string
+
+	// Permissions of the file (defaults to 0o644)
+	permissions?: int
+}
+
 // Forward a network endpoint to and from the client
 _#proxyEndpoint: {
 	$dagger: task: _name: "ProxyEndpoint"

plan/task/outputfile.go

@@ -0,0 +1,63 @@
+package task
+
+import (
+	"context"
+	"fmt"
+	"io/fs"
+	"os"
+
+	"cuelang.org/go/cue"
+	"go.dagger.io/dagger/compiler"
+	"go.dagger.io/dagger/plancontext"
+	"go.dagger.io/dagger/solver"
+)
+
+func init() {
+	Register("OutputFile", func() Task { return &outputFileTask{} })
+}
+
+type outputFileTask struct {
+}
+
+func (c outputFileTask) Run(ctx context.Context, pctx *plancontext.Context, s solver.Solver, v *compiler.Value) (*compiler.Value, error) {
+	var contents []byte
+	var err error
+
+	switch kind := v.Lookup("contents").Kind(); kind {
+	case cue.StringKind:
+		var str string
+		str, err = v.Lookup("contents").String()
+		if err == nil {
+			contents = []byte(str)
+		}
+	case cue.BottomKind:
+		err = fmt.Errorf("contents is not set")
+	default:
+		err = fmt.Errorf("unhandled data type in contents: %s", kind)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	dest, err := v.Lookup("dest").AbsPath()
+	if err != nil {
+		return nil, err
+	}
+
+	perm := fs.FileMode(0644) // default permission
+	if v.Lookup("permissions").Exists() {
+		permissions, err := v.Lookup("permissions").Int64()
+		if err != nil {
+			return nil, err
+		}
+		perm = fs.FileMode(permissions)
+	}
+
+	err = os.WriteFile(dest, contents, perm)
+	if err != nil {
+		return nil, err
+	}
+
+	return compiler.NewValue(), nil
+}

tests/plan.bats

@@ -93,20 +93,64 @@ setup() {
   assert_output --partial "actions.verify.env.FOO: non-concrete value string"
 }
 
-@test "plan/outputs" {
-    cd "$TESTDIR"/plan/outputs
+@test "plan/outputs/directories" {
+    cd "$TESTDIR"/plan/outputs/directories
 
     rm -f "./out/test"
     "$DAGGER" --europa up ./outputs.cue
     assert [ -f "./out/test" ]
 }
 
-@test "plan/outputs relative paths" {
+@test "plan/outputs/directories relative paths" {
     cd "$TESTDIR"/plan
 
-    rm -f "./outputs/out/test"
-    "$DAGGER" --europa up ./outputs/outputs.cue
-    assert [ -f "./outputs/out/test" ]
+    rm -f "./outputs/directories/out/test"
+    "$DAGGER" --europa up ./outputs/directories/outputs.cue
+    assert [ -f "./outputs/directories/out/test" ]
+}
+
+@test "plan/outputs/files normal usage" {
+  cd "$TESTDIR"/plan/outputs/files
+
+  "$DAGGER" --europa up ./usage.cue
+
+  run ./test.sh
+  assert_output "Hello World!"
+
+  run ls -l "./test.sh"
+  assert_output --partial "-rwxr-x---"
+
+  rm -f "./test.sh"
+}
+
+@test "plan/outputs/files relative path" {
+    cd "$TESTDIR"/plan
+
+    "$DAGGER" --europa up ./outputs/files/usage.cue
+    assert [ -f "./outputs/files/test.sh" ]
+
+    rm -f "./outputs/files/test.sh"
+}
+
+@test "plan/outputs/files default permissions" {
+  cd "$TESTDIR"/plan/outputs/files
+
+  "$DAGGER" --europa up ./default_permissions.cue
+
+  run ls -l "./test"
+  assert_output --partial "-rw-r--r--"
+
+  rm -f "./test"
+}
+
+@test "plan/outputs/files no contents" {
+  cd "$TESTDIR"/plan/outputs/files
+
+  run "$DAGGER" --europa up ./no_contents.cue
+  assert_failure
+  assert_output --partial "contents is not set"
+
+  assert [ ! -f "./test" ]
 }
 
 @test "plan/platform" {

tests/plan/outputs/files/default_permissions.cue

@@ -0,0 +1,10 @@
+package main
+
+import "dagger.io/dagger"
+
+dagger.#Plan & {
+	outputs: files: test: {
+		contents: "foobar"
+		dest:     "./test"
+	}
+}

tests/plan/outputs/files/no_contents.cue

@@ -0,0 +1,7 @@
+package main
+
+import "dagger.io/dagger"
+
+dagger.#Plan & {
+	outputs: files: test: dest: "./test"
+}

tests/plan/outputs/files/usage.cue

@@ -0,0 +1,18 @@
+package main
+
+import "dagger.io/dagger"
+
+dagger.#Plan & {
+	outputs: files: {
+		[path=string]: dest: path
+		"test.sh": {
+			contents: """
+				#!/bin/bash
+				set -euo pipefail
+				echo "Hello World!"
+
+				"""
+			permissions: 0o750
+		}
+	}
+}