Refactor Blueprint.WalkModules

* Add safe-version to avoid useless `return nil`;
* Supply `ModulePath` to the "dangerous" version;
* Use `WalkModules` instead of nested for-loops in few cases.

pkg/config/config.go

@@ -89,11 +89,10 @@ func (g DeploymentGroup) Kind() ModuleKind {
 // Module return the module with the given ID
 func (bp *Blueprint) Module(id ModuleID) (*Module, error) {
 	var mod *Module
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		if m.ID == id {
 			mod = m
 		}
-		return nil
 	})
 	if mod == nil {
 		return nil, UnknownModuleError{id}
@@ -106,13 +105,12 @@ func (bp *Blueprint) Module(id ModuleID) (*Module, error) {
 func (bp Blueprint) SuggestModuleIDHint(id ModuleID) (string, bool) {
 	clMod := ""
 	minDist := -1
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		dist := levenshtein.Distance(string(m.ID), string(id), nil)
 		if minDist == -1.0 || dist < minDist {
 			minDist = dist
 			clMod = string(m.ID)
 		}
-		return nil
 	})
 
 	if clMod != "" && minDist <= maxHintDist {
@@ -322,9 +320,8 @@ func (bp Blueprint) ListUnusedVariables() []string {
 	ns := map[string]cty.Value{
 		"vars": bp.Vars.AsObject(),
 	}
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		ns["module_"+string(m.ID)] = m.Settings.AsObject()
-		return nil
 	})
 	for _, v := range bp.Validators {
 		ns["validator_"+v.Validator] = v.Inputs.AsObject()
@@ -398,11 +395,10 @@ func (dc DeploymentConfig) ExportBlueprint(outputFilename string) error {
 
 // addKindToModules sets the kind to 'terraform' when empty.
 func (bp *Blueprint) addKindToModules() {
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		if m.Kind == UnknownKind {
 			m.Kind = TerraformKind
 		}
-		return nil
 	})
 }
 
@@ -440,7 +436,7 @@ func checkModulesAndGroups(bp Blueprint) error {
 
 // validateModuleUseReferences verifies that any used modules exist and
 // are in the correct group
-func validateModuleUseReferences(p modulePath, mod Module, bp Blueprint) error {
+func validateModuleUseReferences(p ModulePath, mod Module, bp Blueprint) error {
 	errs := Errors{}
 	for iu, used := range mod.Use {
 		errs.At(p.Use.At(iu), validateModuleReference(bp, mod, used))
@@ -636,21 +632,29 @@ func IsProductOfModuleUse(v cty.Value) []ModuleID {
 }
 
 // WalkModules walks all modules in the blueprint and calls the walker function
-func (bp *Blueprint) WalkModules(walker func(*Module) error) error {
+func (bp *Blueprint) WalkModules(walker func(ModulePath, *Module) error) error {
 	for ig := range bp.DeploymentGroups {
 		g := &bp.DeploymentGroups[ig]
 		for im := range g.Modules {
+			p := Root.Groups.At(ig).Modules.At(im)
 			m := &g.Modules[im]
-			if err := walker(m); err != nil {
+			if err := walker(p, m); err != nil {
 				return err
 			}
 		}
 	}
 	return nil
 }
 
+func (bp *Blueprint) WalkModulesSafe(walker func(*Module)) {
+	bp.WalkModules(func(_ ModulePath, m *Module) error {
+		walker(m)
+		return nil
+	})
+}
+
 // validate every module setting in the blueprint containing a reference
-func validateModuleSettingReferences(p modulePath, m Module, bp Blueprint) error {
+func validateModuleSettingReferences(p ModulePath, m Module, bp Blueprint) error {
 	errs := Errors{}
 	for k, v := range m.Settings.Items() {
 		for _, r := range valueReferences(v) {

pkg/config/expand.go

@@ -50,9 +50,7 @@ func (dc *DeploymentConfig) expand() error {
 		return err
 	}
 
-	if err := dc.applyGlobalVariables(); err != nil {
-		return err
-	}
+	dc.applyGlobalVariables()
 
 	if err := validateInputsAllModules(dc.Config); err != nil {
 		return err
@@ -64,16 +62,14 @@ func (dc *DeploymentConfig) expand() error {
 
 func validateInputsAllModules(bp Blueprint) error {
 	errs := Errors{}
-	for ig, g := range bp.DeploymentGroups {
-		for im, m := range g.Modules {
-			p := Root.Groups.At(ig).Modules.At(im)
-			errs.Add(validateModuleInputs(p, m, bp))
-		}
-	}
+	bp.WalkModules(func(p ModulePath, m *Module) error {
+		errs.Add(validateModuleInputs(p, *m, bp))
+		return nil
+	})
 	return errs.OrNil()
 }
 
-func validateModuleInputs(mp modulePath, m Module, bp Blueprint) error {
+func validateModuleInputs(mp ModulePath, m Module, bp Blueprint) error {
 	mi := m.InfoOrDie()
 	errs := Errors{}
 	for _, input := range mi.Inputs {
@@ -197,7 +193,7 @@ func useModule(mod *Module, use Module) {
 // applyUseModules applies variables from modules listed in the "use" field
 // when/if applicable
 func (dc *DeploymentConfig) applyUseModules() error {
-	return dc.Config.WalkModules(func(m *Module) error {
+	return dc.Config.WalkModules(func(_ ModulePath, m *Module) error {
 		for _, u := range m.Use {
 			used, err := dc.Config.Module(u)
 			if err != nil { // should never happen
@@ -233,9 +229,8 @@ func (dc *DeploymentConfig) combineLabels() {
 	gl := mergeMaps(defaults, vars.Get(labels).AsValueMap())
 	vars.Set(labels, cty.ObjectVal(gl))
 
-	dc.Config.WalkModules(func(mod *Module) error {
+	dc.Config.WalkModulesSafe(func(mod *Module) {
 		combineModuleLabels(mod, *dc)
-		return nil
 	})
 }
 
@@ -270,7 +265,7 @@ func mergeMaps(ms ...map[string]cty.Value) map[string]cty.Value {
 	return r
 }
 
-func (bp Blueprint) applyGlobalVarsInModule(mod *Module) error {
+func (bp Blueprint) applyGlobalVarsInModule(mod *Module) {
 	mi := mod.InfoOrDie()
 	for _, input := range mi.Inputs {
 		// Module setting exists? Nothing more needs to be done.
@@ -289,15 +284,12 @@ func (bp Blueprint) applyGlobalVarsInModule(mod *Module) error {
 			mod.Settings.Set(input.Name, cty.StringVal(string(mod.ID)))
 		}
 	}
-	return nil
 }
 
 // applyGlobalVariables takes any variables defined at the global level and
 // applies them to module settings if not already set.
-func (dc *DeploymentConfig) applyGlobalVariables() error {
-	return dc.Config.WalkModules(func(mod *Module) error {
-		return dc.Config.applyGlobalVarsInModule(mod)
-	})
+func (dc *DeploymentConfig) applyGlobalVariables() {
+	dc.Config.WalkModulesSafe(dc.Config.applyGlobalVarsInModule)
 }
 
 // AutomaticOutputName generates unique deployment-group-level output names
@@ -400,15 +392,14 @@ func FindIntergroupReferences(v cty.Value, mod Module, bp Blueprint) []Reference
 // find all intergroup references and add them to source Module.Outputs
 func (bp *Blueprint) populateOutputs() {
 	refs := map[Reference]bool{}
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		rs := FindIntergroupReferences(m.Settings.AsObject(), *m, *bp)
 		for _, r := range rs {
 			refs[r] = true
 		}
-		return nil
 	})
 
-	bp.WalkModules(func(m *Module) error {
+	bp.WalkModulesSafe(func(m *Module) {
 		for r := range refs {
 			if r.Module != m.ID {
 				continue // find IGC references pointing to this module
@@ -423,7 +414,6 @@ func (bp *Blueprint) populateOutputs() {
 			})
 
 		}
-		return nil
 	})
 }
 

pkg/config/expand_test.go

@@ -320,9 +320,6 @@ func (s *MySuite) TestApplyGlobalVariables(c *C) {
 	dc := s.getDeploymentConfigForTest()
 	mod := &dc.Config.DeploymentGroups[0].Modules[0]
 
-	// Test no inputs, none required
-	c.Check(dc.applyGlobalVariables(), IsNil)
-
 	// Test no inputs, one required, doesn't exist in globals
 	setTestModuleInfo(*mod, modulereader.ModuleInfo{
 		Inputs: []modulereader.VarInfo{{
@@ -334,25 +331,11 @@ func (s *MySuite) TestApplyGlobalVariables(c *C) {
 
 	// Test no input, one required, exists in globals
 	dc.Config.Vars.Set("gold", cty.StringVal("val"))
-	c.Check(dc.applyGlobalVariables(), IsNil)
+	dc.applyGlobalVariables()
 	c.Assert(
 		mod.Settings.Get("gold"),
 		DeepEquals,
 		GlobalRef("gold").AsExpression().AsValue())
-
-	// Test one input, one required
-	mod.Settings.Set("reqVar", cty.StringVal("val"))
-	c.Assert(dc.applyGlobalVariables(), IsNil)
-
-	// Test one input, none required, exists in globals
-	setTestModuleInfo(*mod, modulereader.ModuleInfo{
-		Inputs: []modulereader.VarInfo{{
-			Name:     "gold",
-			Type:     cty.String,
-			Required: false,
-		}},
-	})
-	c.Assert(dc.applyGlobalVariables(), IsNil)
 }
 
 func (s *zeroSuite) TestIsSimpleVariable(c *C) {

pkg/config/path.go

@@ -156,10 +156,10 @@ type groupPath struct {
 	basePath
 	Name    basePath              `path:".group"`
 	Backend backendPath           `path:".terraform_backend"`
-	Modules arrayPath[modulePath] `path:".modules"`
+	Modules arrayPath[ModulePath] `path:".modules"`
 }
 
-type modulePath struct {
+type ModulePath struct {
 	basePath
 	Source   basePath              `path:".source"`
 	Kind     basePath              `path:".kind"`

pkg/config/validate.go

@@ -82,7 +82,7 @@ func validateVars(vars Dict) error {
 	return errs.OrNil()
 }
 
-func validateModule(p modulePath, m Module, bp Blueprint) error {
+func validateModule(p ModulePath, m Module, bp Blueprint) error {
 	// Source/Kind validations are required to pass to perform other validations
 	if m.Source == "" {
 		return BpError{p.Source, EmptyModuleSource}
@@ -113,7 +113,7 @@ func validateModule(p modulePath, m Module, bp Blueprint) error {
 		OrNil()
 }
 
-func validateOutputs(p modulePath, mod Module, info modulereader.ModuleInfo) error {
+func validateOutputs(p ModulePath, mod Module, info modulereader.ModuleInfo) error {
 	errs := Errors{}
 	outputs := info.GetOutputsAsMap()
 
@@ -133,7 +133,7 @@ type moduleVariables struct {
 }
 
 func validateSettings(
-	p modulePath,
+	p ModulePath,
 	mod Module,
 	info modulereader.ModuleInfo) error {
 

pkg/validators/cloud.go

@@ -188,12 +188,11 @@ func testApisEnabled(bp config.Blueprint, inputs config.Dict) error {
 		return err
 	}
 	apis := map[string]bool{}
-	bp.WalkModules(func(m *config.Module) error {
+	bp.WalkModulesSafe(func(m *config.Module) {
 		services := m.InfoOrDie().Metadata.Spec.Requirements.Services
 		for _, api := range services {
 			apis[api] = true
 		}
-		return nil
 	})
 	return TestApisEnabled(p, maps.Keys(apis))
 }

pkg/validators/semantic.go

@@ -26,19 +26,15 @@ func testModuleNotUsed(bp config.Blueprint, inputs config.Dict) error {
 		return err
 	}
 	errs := config.Errors{}
-	for ig, g := range bp.DeploymentGroups {
-		for im, m := range g.Modules {
-			ums := m.ListUnusedModules()
-			p := config.Root.Groups.At(ig).Modules.At(im).Use
-
-			for iu, u := range m.Use {
-				if slices.Contains(ums, u) {
-					errs.At(p.At(iu), fmt.Errorf(unusedModuleMsg, m.ID, u))
-				}
+	bp.WalkModules(func(p config.ModulePath, m *config.Module) error {
+		ums := m.ListUnusedModules()
+		for iu, u := range m.Use {
+			if slices.Contains(ums, u) {
+				errs.At(p.Use.At(iu), fmt.Errorf(unusedModuleMsg, m.ID, u))
 			}
 		}
-	}
-
+		return nil
+	})
 	return errs.OrNil()
 }