refactor: hello

Author: softwaredevelop

hello/main.go

@@ -1,50 +1,46 @@
-// Package main provides a generated module for Hello functions.
+// A Dagger reference module demonstrating basic module concepts and return types.
 //
-// This module has been generated via dagger init and serves as a reference to
-// basic module structure as you get started with Dagger.
-//
-// Two functions have been pre-created. You can modify, delete, or add to them,
-// as needed. They demonstrate usage of arguments and return types using simple
-// echo and grep commands. The functions can be called from the dagger CLI or
-// from one of the SDKs.
-//
-// The first line in this comment block is a short description line and the
-// rest is a long description with more detail on the module's purpose or usage,
-// if appropriate. All modules should have a short description.
+// This module serves as a learning template showing how to return strings,
+// chain containers, generate files, and use default or optional arguments.
 package main
 
 import (
+	"context"
 	"dagger/hello/internal/dagger"
+	"fmt"
 )
 
 const (
-	defaultImageRepository = "busybox:uclibc"
+	defaultImageRepository = "cgr.dev/chainguard/wolfi-base:latest"
 )
 
-// Hello is a struct that provides echo functions.
+// Hello provides greeting and demonstration functions.
 type Hello struct {
 	// +private
 	Image string
 	// +private
+	Greeting string
+	// +private
 	Ctr *dagger.Container
 }
 
-// New creates a new instance of the Hello struct.
-// If the ctr parameter is nil, it will create a new dagger.Container using the "busybox:uclibc" image.
-// The stringArg parameter is an optional argument that specifies a string value.
-// If not provided, it will default to "Hello, Daggerverse!".
-// The function returns a pointer to the created Hello struct.
+// New creates a new instance of the Hello module.
 func New(
-	// Custom image reference in "repository:tag" format to use as a base container.
+	// Custom image reference in "repository:tag" format.
 	// +optional
 	image string,
+	// Default greeting word to use (e.g. "Hello", "Hola", "Szia").
+	// +default="Hello"
+	// +optional
+	greeting string,
 ) *Hello {
 	return &Hello{
-		Image: image,
+		Image:    image,
+		Greeting: greeting,
 	}
 }
 
-// Container returns the underlying Dagger container
+// container returns the underlying Dagger container, lazily initialized.
 func (m *Hello) container() *dagger.Container {
 	if m.Ctr != nil {
 		return m.Ctr
@@ -59,21 +55,51 @@ func (m *Hello) container() *dagger.Container {
 	return m.Ctr
 }
 
-// HelloString returns the string value provided to the Hello struct.
-func (m *Hello) HelloString(
-	// StringArg is the string value to be printed.
-	StringArg string,
-) *dagger.Container {
+// Message returns a greeting string using pure Go (runs instantly without containers).
+func (m *Hello) Message(
+	// Name of the person or entity to greet.
+	// +default="Daggerverse"
+	// +optional
+	name string,
+) string {
+	return fmt.Sprintf("%s, %s!", m.Greeting, name)
+}
+
+// Say executes an echo command inside the container and returns stdout.
+func (m *Hello) Say(
+	ctx context.Context,
+	// Name to greet inside the container.
+	// +default="Daggerverse"
+	// +optional
+	name string,
+) (string, error) {
+	msg := fmt.Sprintf("%s, %s!", m.Greeting, name)
 	return m.container().
-		WithExec([]string{"echo", StringArg})
+		WithExec([]string{"echo", msg}).
+		Stdout(ctx)
 }
 
-// HelloContainer executes a container with the provided string value.
-func (m *Hello) HelloContainer(
-	// StringArg is the string value to be printed.
-	StringArg string,
+// Terminal returns the container prepared with the message, ready for chaining or interactive shell.
+func (m *Hello) Terminal(
+	// Message to echo when container starts.
+	// +default="Welcome to Dagger!"
+	// +optional
+	message string,
 ) *dagger.Container {
 	return m.container().
-		From("cgr.dev/chainguard/wolfi-base:latest").
-		WithExec([]string{"echo", StringArg})
+		WithExec([]string{"echo", message})
+}
+
+// Write generates a greeting text file inside Dagger and returns it as an artifact.
+func (m *Hello) Write(
+	// Name to greet in the generated file.
+	// +default="Daggerverse"
+	// +optional
+	name string,
+) *dagger.File {
+	content := fmt.Sprintf("%s, %s!\nGenerated by Dagger.\n", m.Greeting, name)
+
+	return dag.Directory().
+		WithNewFile("greeting.txt", content).
+		File("greeting.txt")
 }

hello/test/main.go

@@ -1,81 +1,92 @@
-// A generated module for Test functions
-//
-// This module has been generated via dagger init and serves as a reference to
-// basic module structure as you get started with Dagger.
-//
-// Two functions have been pre-created. You can modify, delete, or add to them,
-// as needed. They demonstrate usage of arguments and return types using simple
-// echo and grep commands. The functions can be called from the dagger CLI or
-// from one of the SDKs.
-//
-// The first line in this comment block is a short description line and the
-// rest is a long description with more detail on the module's purpose or usage,
-// if appropriate. All modules should have a short description.
+// Package main provides tests for the Hello reference module.
 package main
 
 import (
 	"context"
 	"dagger/hello/test/internal/dagger"
+	"errors"
+	"strings"
 
 	"github.com/sourcegraph/conc/pool"
 )
 
-// Test is a module for running tests.
+// Test provides tests for the Hello module.
 type Test struct{}
 
-// All runs all tests.
+// All runs all tests concurrently.
 func (m *Test) All(ctx context.Context) error {
-	p := pool.New().WithContext(ctx)
+	p := pool.New().WithErrors().WithContext(ctx)
 
-	p.Go(m.HelloContainer)
-	p.Go(m.HelloStringContainer)
-	p.Go(m.HelloString)
+	p.Go(m.TestMessage)
+	p.Go(m.TestSay)
+	p.Go(m.TestTerminal)
+	p.Go(m.TestWrite)
+	p.Go(m.TestCustomGreeting)
 
 	return p.Wait()
 }
 
-// HelloContainer tests the HelloContainer function.
-func (m *Test) HelloContainer(ctx context.Context) error {
-
-	argString := "Hello, Daggerverse!"
-	_, err := dag.Hello().HelloContainer(argString).Sync(ctx)
-
+// TestMessage asserts that the pure Go Message function returns the expected string.
+func (m *Test) TestMessage(ctx context.Context) error {
+	msg, err := dag.Hello().Message(ctx)
 	if err != nil {
 		return err
 	}
 
+	if msg != "Hello, Daggerverse!" {
+		return errors.New("unexpected message output: " + msg)
+	}
 	return nil
-
 }
 
-// HelloStringContainer tests the HelloString function.
-func (m *Test) HelloStringContainer(ctx context.Context) error {
-
-	argString := "Hello, Daggerverse!"
-	_, err := dag.Hello(
-		dagger.HelloOpts{
-			Image: "cgr.dev/chainguard/wolfi-base:latest",
-		},
-	).HelloString(argString).Sync(ctx)
-
+// TestSay asserts that the container execution produces the correct stdout.
+func (m *Test) TestSay(ctx context.Context) error {
+	stdout, err := dag.Hello().Say(ctx, dagger.HelloSayOpts{
+		Name: "Gopher",
+	})
 	if err != nil {
 		return err
 	}
 
+	if !strings.Contains(stdout, "Hello, Gopher!") {
+		return errors.New("expected stdout to contain 'Hello, Gopher!', got: " + stdout)
+	}
 	return nil
+}
 
+// TestTerminal asserts that the returned container executes successfully.
+func (m *Test) TestTerminal(ctx context.Context) error {
+	_, err := dag.Hello().Terminal().Sync(ctx)
+	return err
 }
 
-// HelloString tests the HelloString function.
-func (m *Test) HelloString(ctx context.Context) error {
+// TestWrite asserts that a valid file artifact is generated with expected contents.
+func (m *Test) TestWrite(ctx context.Context) error {
+	file := dag.Hello().Write()
+	content, err := file.Contents(ctx)
+	if err != nil {
+		return err
+	}
 
-	argString := "Hello, Daggerverse!"
-	_, err := dag.Hello().HelloString(argString).Sync(ctx)
+	if !strings.Contains(content, "Generated by Dagger.") {
+		return errors.New("file content does not match expected output")
+	}
+	return nil
+}
 
+// TestCustomGreeting tests the constructor options.
+func (m *Test) TestCustomGreeting(ctx context.Context) error {
+	msg, err := dag.Hello(dagger.HelloOpts{
+		Greeting: "Hello",
+	}).Message(ctx, dagger.HelloMessageOpts{
+		Name: "World",
+	})
 	if err != nil {
 		return err
 	}
 
+	if msg != "Hello, World!" {
+		return errors.New("expected 'Hello, World!', got: " + msg)
+	}
 	return nil
-
 }