Allow customizable number of expansions

Updates #66

internal/compiler/v2/compiler_v2.go

@@ -16,10 +16,13 @@ import (
 var _ compiler.Compiler = &CompilerV2{}
 
 type CompilerV2 struct {
-	Dir          string
+	Dir string
+
 	Taskvars     taskfile.Vars
 	TaskfileVars taskfile.Vars
 
+	Expansions int
+
 	Logger *logger.Logger
 
 	dynamicCache   map[string]string
@@ -34,14 +37,11 @@ type CompilerV2 struct {
 // 5. Environment variables
 func (c *CompilerV2) GetVariables(t *taskfile.Task, call taskfile.Call) (taskfile.Vars, error) {
 	vr := varResolver{c: c, vars: compiler.GetEnviron()}
-	vr.merge(c.Taskvars)
-	vr.merge(c.Taskvars)
-	vr.merge(c.TaskfileVars)
-	vr.merge(c.TaskfileVars)
-	vr.merge(call.Vars)
-	vr.merge(call.Vars)
-	vr.merge(t.Vars)
-	vr.merge(t.Vars)
+	for _, vars := range []taskfile.Vars{c.Taskvars, c.TaskfileVars, call.Vars, t.Vars} {
+		for i := 0; i < c.Expansions; i++ {
+			vr.merge(vars)
+		}
+	}
 	return vr.vars, vr.err
 }
 

internal/taskfile/taskfile.go

@@ -2,9 +2,10 @@ package taskfile
 
 // Taskfile represents a Taskfile.yml
 type Taskfile struct {
-	Version string
-	Vars    Vars
-	Tasks   Tasks
+	Version    string
+	Expansions int
+	Vars       Vars
+	Tasks      Tasks
 }
 
 // UnmarshalYAML implements yaml.Unmarshaler interface
@@ -15,15 +16,20 @@ func (tf *Taskfile) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	}
 
 	var taskfile struct {
-		Version string
-		Vars    Vars
-		Tasks   Tasks
+		Version    string
+		Expansions int
+		Vars       Vars
+		Tasks      Tasks
 	}
 	if err := unmarshal(&taskfile); err != nil {
 		return err
 	}
 	tf.Version = taskfile.Version
+	tf.Expansions = taskfile.Expansions
 	tf.Vars = taskfile.Vars
 	tf.Tasks = taskfile.Tasks
+	if tf.Expansions <= 0 {
+		tf.Expansions = 2
+	}
 	return nil
 }

task.go

@@ -112,6 +112,7 @@ func (e *Executor) setup() error {
 			Dir:          e.Dir,
 			Taskvars:     e.taskvars,
 			TaskfileVars: e.Taskfile.Vars,
+			Expansions:   e.Taskfile.Expansions,
 			Logger:       e.Logger,
 		}