From 9f33594adb0b802a13c94558a5b53b552422c628 Mon Sep 17 00:00:00 2001
From: Joel Longtine <joel@dagger.io>
Date: Thu, 18 Nov 2021 15:52:25 -0700
Subject: [PATCH 1/2] Allow tasks to be hidden fields

Signed-off-by: Joel Longtine <joel@longtine.io>
---
 tools/flow/flow.go  | 2 ++
 tools/flow/tasks.go | 8 +++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/flow/flow.go b/tools/flow/flow.go
index 17eabe4ea45..e0703229ecd 100644
--- a/tools/flow/flow.go
+++ b/tools/flow/flow.go
@@ -135,6 +135,8 @@ type Config struct {
 	// concrete and cannot change.
 	IgnoreConcrete bool
 
+	FindHiddenTasks bool
+
 	// UpdateFunc is called whenever the information in the controller is
 	// updated. This includes directly after initialization. The task may be
 	// nil if this call is not the result of a task completing.
diff --git a/tools/flow/tasks.go b/tools/flow/tasks.go
index 519a38659dc..d3c4b397e2c 100644
--- a/tools/flow/tasks.go
+++ b/tools/flow/tasks.go
@@ -68,7 +68,13 @@ func (c *Controller) findRootTasks(v cue.Value) {
 		return
 	}
 
-	for iter, _ := v.Fields(); iter.Next(); {
+	opts := []cue.Option{}
+
+	if c.cfg.FindHiddenTasks {
+		opts = append(opts, cue.Hidden(true))
+	}
+
+	for iter, _ := v.Fields(opts...); iter.Next(); {
 		c.findRootTasks(iter.Value())
 	}
 }

From 14f1333393259853872bd4ff9bbac0a7e6a04188 Mon Sep 17 00:00:00 2001
From: Joel Longtine <joel@dagger.io>
Date: Fri, 19 Nov 2021 14:55:46 -0700
Subject: [PATCH 2/2] Add hidden field tasks test case

Signed-off-by: Joel Longtine <joel@longtine.io>
---
 tools/flow/example_basic_test.go | 35 ++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/tools/flow/example_basic_test.go b/tools/flow/example_basic_test.go
index b0eeb6c2327..c1958c4b3e8 100644
--- a/tools/flow/example_basic_test.go
+++ b/tools/flow/example_basic_test.go
@@ -33,6 +33,41 @@ func Example() {
 	// setting b.output to "hello hello world"
 }
 
+func ExampleHidden() {
+	var r cue.Runtime
+	inst, err := r.Compile("example.cue", `
+	a: {
+		input: "world"
+		output: string
+	}
+	b: {
+		input: a.output
+		output: string
+	}
+	_c: {
+		input: b.output
+		output: string
+	}
+	d: {
+		input: _c.output
+		output: string
+	}
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	controller := flow.New(&flow.Config{FindHiddenTasks: true}, inst, ioTaskFunc)
+	// controller := flow.New(nil, inst, ioTaskFunc)
+	if err := controller.Run(context.Background()); err != nil {
+		log.Fatal(err)
+	}
+	// Output:
+	// setting a.output to "hello world"
+	// setting b.output to "hello hello world"
+	// setting _c.output to "hello hello hello world"
+	// setting d.output to "hello hello hello hello world"
+}
+
 func ioTaskFunc(v cue.Value) (flow.Runner, error) {
 	inputPath := cue.ParsePath("input")