Fix incorrect stability labels and add test (#6541)

* Fix incorrect stability levels

* Add more tests

component/otelcol/connector/host_info/host_info.go

@@ -17,7 +17,7 @@ import (
 func init() {
 	component.Register(component.Registration{
 		Name:      "otelcol.connector.host_info",
-		Stability: featuregate.StabilityStable,
+		Stability: featuregate.StabilityExperimental,
 		Args:      Arguments{},
 		Exports:   otelcol.ConsumerExports{},
 

component/otelcol/processor/resourcedetection/resourcedetection.go

@@ -33,7 +33,7 @@ import (
 func init() {
 	component.Register(component.Registration{
 		Name:      "otelcol.processor.resourcedetection",
-		Stability: featuregate.StabilityStable,
+		Stability: featuregate.StabilityBeta,
 		Args:      Arguments{},
 		Exports:   otelcol.ConsumerExports{},
 

component/pyroscope/java/java.go

@@ -23,7 +23,7 @@ const (
 func init() {
 	component.Register(component.Registration{
 		Name:      "pyroscope.java",
-		Stability: featuregate.StabilityStable,
+		Stability: featuregate.StabilityBeta,
 		Args:      Arguments{},
 
 		Build: func(opts component.Options, args component.Arguments) (component.Component, error) {

component/pyroscope/java/java_stub.go

@@ -13,7 +13,7 @@ import (
 func init() {
 	component.Register(component.Registration{
 		Name:      "pyroscope.java",
-		Stability: featuregate.StabilityStable,
+		Stability: featuregate.StabilityBeta,
 		Args:      Arguments{},
 
 		Build: func(opts component.Options, args component.Arguments) (component.Component, error) {

pkg/flow/internal/testcomponents/experimental.go

@@ -0,0 +1,36 @@
+package testcomponents
+
+import (
+	"context"
+
+	"github.com/go-kit/log"
+	"github.com/grafana/agent/component"
+	"github.com/grafana/agent/internal/featuregate"
+)
+
+func init() {
+	component.Register(component.Registration{
+		Name:      "testcomponents.experimental",
+		Stability: featuregate.StabilityExperimental,
+
+		Build: func(opts component.Options, args component.Arguments) (component.Component, error) {
+			return &Experimental{log: opts.Logger}, nil
+		},
+	})
+}
+
+// Experimental is a test component that is marked as experimental. Used to verify stability level checking.
+type Experimental struct {
+	log log.Logger
+}
+
+func (e *Experimental) Run(ctx context.Context) error {
+	e.log.Log("msg", "running experimental component")
+	<-ctx.Done()
+	return nil
+}
+
+func (e *Experimental) Update(args component.Arguments) error {
+	e.log.Log("msg", "updating experimental component")
+	return nil
+}

pkg/flow/testdata/import_error/import_error_3.txtar

@@ -0,0 +1,14 @@
+Use of an imported component with too low stability level propagates the error
+
+-- main.river --
+
+import.string "testImport" {
+	content = ` declare "a" {
+		testcomponents.experimental "unstable" {}
+	}`
+}
+
+testImport.a "cc" {}
+
+-- error --
+component "testcomponents.experimental" is at stability level "experimental", which is below the minimum allowed stability level "beta"

pkg/flow/testdata/import_error/import_error_4.txtar

@@ -0,0 +1,18 @@
+Use of a nested declare component with too low stability level propagates the error
+
+-- main.river --
+
+declare "a" {
+
+  declare "b" {
+		testcomponents.experimental "unstable" {}
+  }
+
+  b "cc" {}
+
+}
+
+a "cc" {}
+
+-- error --
+component "testcomponents.experimental" is at stability level "experimental", which is below the minimum allowed stability level "beta"

pkg/flow/testdata/import_file/import_file_14.txtar

@@ -0,0 +1,38 @@
+Import module with an unused component that has too low stability level
+
+-- main.river --
+testcomponents.count "inc" {
+	frequency = "10ms"
+	max = 10
+}
+
+import.file "testImport" {
+	filename = "module.river"
+}
+
+testImport.a "cc" {
+	input = testcomponents.count.inc.count
+}
+
+testcomponents.summation "sum" {
+	input = testImport.a.cc.output
+}
+
+-- module.river --
+
+declare "unused" {
+  testcomponents.experimental "unused" {}
+}
+
+declare "a" {
+	argument "input" {}
+
+  testcomponents.passthrough "pt" {
+		input = argument.input.value
+		lag = "1ms"
+	}
+
+	export "output" {
+		value = testcomponents.passthrough.pt.output
+	}
+}

pkg/flow/testdata/import_file/import_file_15.txtar

@@ -0,0 +1,84 @@
+Import nested module with an unused component with too low stability level
+
+-- main.river --
+testcomponents.count "inc" {
+	frequency = "10ms"
+	max = 10
+}
+
+import.file "testImport" {
+	filename = "module.river"
+}
+
+testImport.a "cc" {
+	input = testcomponents.count.inc.count
+}
+
+testcomponents.summation "sum" {
+	input = testImport.a.cc.output
+}
+
+-- module.river --
+import.file "testImport" {
+	filename = "nested_module.river"
+}
+
+declare "a" {
+	argument "input" {}
+
+	testImport.a "cc" {
+		input = argument.input.value
+	}
+
+	export "output" {
+		value = testImport.a.cc.output
+	}
+}
+
+-- nested_module.river --
+declare "a" {
+	argument "input" {}
+
+	testcomponents.passthrough "pt" {
+		input = argument.input.value
+		lag = "1ms"
+	}
+
+	export "output" {
+		value = testcomponents.passthrough.pt.output
+	}
+}
+
+-- other_nested_module.river --
+declare "unused" {
+  testcomponents.experimental "unused" {}
+}
+
+declare "a" {
+	argument "input" {}
+
+	export "output" {
+		value = -argument.input.value
+	}
+}
+
+-- update/module.river --
+import.file "testImport" {
+	filename = "other_nested_module.river"
+}
+
+declare "unused" {
+  testcomponents.experimental "unused" {}
+}
+
+declare "a" {
+	argument "input" {}
+
+	testImport.a "cc" {
+		input = argument.input.value
+	}
+
+	export "output" {
+		value = testImport.a.cc.output
+	}
+}