Source Refactor (#117)

* Port source refactor changes over to new branch based on main

* Remove unused Result type

* Rename tests

* Reconcile source changes with new source_tests

* Remove comment out test code

* Move filtering out of GetSource() and update tests

* Add source inline support to refactor

* Address review feedback, fix bug with not filtering sources before passing into nested build

frontend/debug/handle_sources.go

@@ -19,10 +19,7 @@ func HandleSources(ctx context.Context, gwc client.Client, spec *dalec.Spec) (cl
 
 	sources := make([]llb.State, 0, len(spec.Sources))
 	for name, src := range spec.Sources {
-		name := name
-		src := src
-		f := dalec.Source2LLBGetter(spec, src, name)
-		st, err := f(sOpt)
+		st, err := src.AsState(name, sOpt)
 		if err != nil {
 			return nil, nil, err
 		}

frontend/rpm/handle_sources.go

@@ -104,7 +104,7 @@ func Dalec2SourcesLLB(spec *dalec.Spec, sOpt dalec.SourceOpts, opts ...llb.Const
 		}
 
 		pg := dalec.ProgressGroup("Add spec source: " + k + " " + s)
-		st, err := dalec.Source2LLBGetter(spec, src, k)(sOpt, append(opts, pg)...)
+		st, err := src.AsState(k, sOpt, append(opts, pg)...)
 		if err != nil {
 			return nil, err
 		}

frontend/test_runner.go

@@ -58,7 +58,7 @@ func RunTests(ctx context.Context, client gwclient.Client, spec *dalec.Spec, ref
 		pg := llb.ProgressGroup(identity.NewID(), "Test: "+path.Join(target, test.Name), false)
 
 		for _, sm := range test.Mounts {
-			st, err := dalec.Source2LLBGetter(spec, sm.Spec, sm.Dest)(sOpt, pg)
+			st, err := sm.Spec.AsMount(sm.Dest, sOpt, pg)
 			if err != nil {
 				return err
 			}

helpers.go

@@ -140,10 +140,9 @@ func (f localOptionFunc) SetLocalOption(li *llb.LocalInfo) {
 	f(li)
 }
 
-func localIncludeExcludeMerge(src *Source) localOptionFunc {
+func localIncludeExcludeMerge(includes []string, excludes []string) localOptionFunc {
 	return func(li *llb.LocalInfo) {
-		if len(src.Excludes) > 0 {
-			excludes := src.Excludes
+		if len(excludes) > 0 {
 			if li.ExcludePatterns != "" {
 				var ls []string
 				if err := json.Unmarshal([]byte(li.ExcludePatterns), &ls); err != nil {
@@ -154,8 +153,7 @@ func localIncludeExcludeMerge(src *Source) localOptionFunc {
 			llb.ExcludePatterns(excludes).SetLocalOption(li)
 		}
 
-		if len(src.Includes) > 0 {
-			includes := src.Includes
+		if len(includes) > 0 {
 			if li.IncludePatterns != "" {
 				var ls []string
 				if err := json.Unmarshal([]byte(li.IncludePatterns), &ls); err != nil {