introduce WithSelectedJob

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

Author: ndeloof

types/project.go

@@ -550,6 +550,31 @@ func (p *Project) WithSelectedServices(names []string, options ...DependencyOpti
 	return newProject, nil
 }
 
+// WithSelectedJob returns a new Project containing only the services required
+// by the named job's DependsOn. The job itself is NOT added to Services.
+func (p *Project) WithSelectedJob(name string, options ...DependencyOption) (*Project, error) {
+	job, ok := p.Jobs[name]
+	if !ok {
+		return nil, fmt.Errorf("no such job: %s", name)
+	}
+
+	var deps []string
+	for dep := range job.DependsOn {
+		deps = append(deps, dep)
+	}
+
+	if len(deps) == 0 {
+		// Job has no service dependencies: return project with all services disabled
+		newProject := p.deepCopy()
+		for name := range newProject.Services {
+			newProject = newProject.WithServicesDisabled(name)
+		}
+		return newProject, nil
+	}
+
+	return p.WithSelectedServices(deps, options...)
+}
+
 // WithServicesDisabled removes from the project model the given services and their references in all dependencies
 // It returns a new Project instance with the changes and keep the original Project unchanged
 func (p *Project) WithServicesDisabled(names ...string) *Project {

types/project_test.go

@@ -522,6 +522,75 @@ func TestProject_WithServicesEnvironmentResolved(t *testing.T) {
 	})
 }
 
+func TestWithSelectedJob(t *testing.T) {
+	project := &Project{
+		Services: Services{
+			"db": {
+				Name: "db",
+				ContainerSpec: ContainerSpec{
+					Image: "postgres",
+				},
+			},
+			"redis": {
+				Name: "redis",
+				ContainerSpec: ContainerSpec{
+					Image: "redis",
+				},
+			},
+			"web": {
+				Name: "web",
+				ContainerSpec: ContainerSpec{
+					Image: "myapp",
+					DependsOn: DependsOnConfig{
+						"db": {Condition: "service_healthy"},
+					},
+				},
+			},
+		},
+		Jobs: Jobs{
+			"migrate": {
+				Name: "migrate",
+				ContainerSpec: ContainerSpec{
+					Image:   "myapp",
+					Command: ShellCommand{"migrate"},
+					DependsOn: DependsOnConfig{
+						"db": {Condition: "service_healthy"},
+					},
+				},
+			},
+			"seed": {
+				Name: "seed",
+				ContainerSpec: ContainerSpec{
+					Image: "myapp",
+				},
+			},
+		},
+	}
+
+	t.Run("job with dependencies includes only required services", func(t *testing.T) {
+		result, err := project.WithSelectedJob("migrate")
+		assert.NilError(t, err)
+		assert.Equal(t, len(result.Services), 1)
+		_, hasDB := result.Services["db"]
+		assert.Assert(t, hasDB)
+		_, hasRedis := result.Services["redis"]
+		assert.Assert(t, !hasRedis)
+		_, hasWeb := result.Services["web"]
+		assert.Assert(t, !hasWeb)
+	})
+
+	t.Run("job without dependencies returns empty services", func(t *testing.T) {
+		result, err := project.WithSelectedJob("seed")
+		assert.NilError(t, err)
+		assert.Equal(t, len(result.Services), 0)
+	})
+
+	t.Run("unknown job returns error", func(t *testing.T) {
+		_, err := project.WithSelectedJob("nonexistent")
+		assert.ErrorContains(t, err, "no such job: nonexistent")
+	})
+}
+
 func ptr[T any](s T) *T {
 	return &s
 }