internal/config: replace viper with custom config loader

go.mod

@@ -33,7 +33,6 @@ require (
 	github.com/opencontainers/image-spec v1.1.0
 	github.com/rogpeppe/go-internal v1.12.0
 	github.com/rwtodd/Go.Sed v0.0.0-20240405174034-bb8ed5da0fd0
-	github.com/spf13/afero v1.11.0
 	github.com/stateful/godotenv v0.0.0-20240309032207-c7bc0b812915
 	github.com/vektah/gqlparser/v2 v2.5.11
 	github.com/yuin/goldmark v1.7.1
@@ -64,34 +63,25 @@ require (
 	github.com/envoyproxy/protoc-gen-validate v1.0.4 // indirect
 	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
-	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/go-logr/logr v1.4.1 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/google/cel-go v0.20.1 // indirect
-	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/magiconair/properties v1.8.7 // indirect
-	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/term v0.5.0 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/sagikazarmark/locafero v0.4.0 // indirect
-	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
-	github.com/sourcegraph/conc v0.3.0 // indirect
-	github.com/spf13/cast v1.6.0 // indirect
 	github.com/stoewer/go-strcase v1.3.0 // indirect
-	github.com/subosito/gotenv v1.6.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.51.0 // indirect
 	go.opentelemetry.io/otel v1.26.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.24.0 // indirect
 	go.opentelemetry.io/otel/metric v1.26.0 // indirect
 	go.opentelemetry.io/otel/sdk v1.24.0 // indirect
 	go.opentelemetry.io/otel/trace v1.26.0 // indirect
 	golang.org/x/net v0.25.0 // indirect
+	golang.org/x/time v0.5.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20240513163218-0867130af1f8 // indirect
-	gopkg.in/ini.v1 v1.67.0 // indirect
 	gotest.tools/v3 v3.5.1 // indirect
 )
 
@@ -151,7 +141,6 @@ require (
 	github.com/pkg/term v1.2.0-beta.2.0.20211217091447-1a4a3b719465
 	github.com/spf13/cobra v1.8.0
 	github.com/spf13/pflag v1.0.5
-	github.com/spf13/viper v1.18.2
 	github.com/stretchr/testify v1.9.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/sync v0.7.0

go.sum

@@ -98,8 +98,6 @@ github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
-github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
-github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/fullstorydev/grpcurl v1.9.1 h1:YxX1aCcCc4SDBQfj9uoWcTLe8t4NWrZe1y+mk83BQgo=
 github.com/fullstorydev/grpcurl v1.9.1/go.mod h1:i8gKLIC6s93WdU3LSmkE5vtsCxyRmihUj5FK1cNW5EM=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
@@ -160,8 +158,6 @@ github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 h1:Wqo399gCIufwto+VfwCSvsnfGpF
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0/go.mod h1:qmOFXW2epJhM0qSnUUYpldc7gVz2KMQwJ/QYCDIa7XU=
 github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
 github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
-github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
-github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/henvic/httpretty v0.1.3 h1:4A6vigjz6Q/+yAfTD4wqipCv+Px69C7Th/NhT0ApuU8=
 github.com/henvic/httpretty v0.1.3/go.mod h1:UUEv7c2kHZ5SPQ51uS3wBpzPDibg2U3Y+IaXyHy5GBg=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -187,8 +183,6 @@ github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
 github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
-github.com/magiconair/properties v1.8.7 h1:IeQXZAiQcpL9mgcAe1Nu6cX9LLw6ExEHKjN0VQdvPDY=
-github.com/magiconair/properties v1.8.7/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
@@ -201,8 +195,6 @@ github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZ
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d h1:5PJl274Y63IEHC+7izoQE9x6ikvDFZS2mDVS3drnohI=
 github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d/go.mod h1:01TrycV0kFyexm33Z7vhZRXopbI8J3TDReVlkTgMUxE=
-github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
-github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/moby/docker-image-spec v1.3.1 h1:jMKff3w6PgbfSa69GfNg+zN/XLhfXJGnEx3Nl2EsFP0=
 github.com/moby/docker-image-spec v1.3.1/go.mod h1:eKmb5VW8vQEh/BAr2yvVNvuiJuY6UIocYsFu/DxxRpo=
 github.com/moby/term v0.5.0 h1:xt8Q1nalod/v7BqbG21f8mQPqH+xAaC9C3N3wfWbVP0=
@@ -248,10 +240,6 @@ github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/rwtodd/Go.Sed v0.0.0-20240405174034-bb8ed5da0fd0 h1:Sm5QvnDuFhkajkdjAHX51h+gyuv+LmkjX//zjpZwIvA=
 github.com/rwtodd/Go.Sed v0.0.0-20240405174034-bb8ed5da0fd0/go.mod h1:c6qgHcSUeSISur4+Kcf3WYTvpL07S8eAsoP40hDiQ1I=
-github.com/sagikazarmark/locafero v0.4.0 h1:HApY1R9zGo4DBgr7dqsTH/JJxLTTsOt7u6keLGt6kNQ=
-github.com/sagikazarmark/locafero v0.4.0/go.mod h1:Pe1W6UlPYUk/+wc/6KFhbORCfqzgYEpgQ3O5fPuL3H4=
-github.com/sagikazarmark/slog-shim v0.1.0 h1:diDBnUNK9N/354PgrxMywXnAwEr1QZcOr6gto+ugjYE=
-github.com/sagikazarmark/slog-shim v0.1.0/go.mod h1:SrcSrq8aKtyuqEI1uvTDTK1arOWRIczQRv+GVI1AkeQ=
 github.com/sahilm/fuzzy v0.1.1 h1:ceu5RHF8DGgoi+/dR5PsECjCDH1BE3Fnmpo7aVXOdRA=
 github.com/sahilm/fuzzy v0.1.1/go.mod h1:VFvziUEIMCrT6A6tw2RFIXPXXmzXbOsSHF0DOI8ZK9Y=
 github.com/sergi/go-diff v1.3.2-0.20230802210424-5b0b94c5c0d3 h1:n661drycOFuPLCN3Uc8sB6B/s6Z4t2xvBgU1htSHuq8=
@@ -261,18 +249,10 @@ github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/skeema/knownhosts v1.2.2 h1:Iug2P4fLmDw9f41PB6thxUkNUkJzB5i+1/exaj40L3A=
 github.com/skeema/knownhosts v1.2.2/go.mod h1:xYbVRSPxqBZFrdmDyMmsOs+uX1UZC3nTN3ThzgDxUwo=
-github.com/sourcegraph/conc v0.3.0 h1:OQTbbt6P72L20UqAkXXuLOj79LfEanQ+YQFNpLA9ySo=
-github.com/sourcegraph/conc v0.3.0/go.mod h1:Sdozi7LEKbFPqYX2/J+iBAM6HpqSLTASQIKqDmF7Mt0=
-github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=
-github.com/spf13/afero v1.11.0/go.mod h1:GH9Y3pIexgf1MTIWtNGyogA5MwRIDXGUr+hbWNoBjkY=
-github.com/spf13/cast v1.6.0 h1:GEiTHELF+vaR5dhz3VqZfFSzZjYbgeKDpBxQVS4GYJ0=
-github.com/spf13/cast v1.6.0/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
 github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
 github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-github.com/spf13/viper v1.18.2 h1:LUXCnvUvSM6FXAsj6nnfc8Q2tp1dIgUfY9Kc8GsSOiQ=
-github.com/spf13/viper v1.18.2/go.mod h1:EKmWIqdnk5lOcmR72yw6hS+8OPYcwD0jteitLMVB+yk=
 github.com/stateful/godotenv v0.0.0-20240309032207-c7bc0b812915 h1:rBwOH8hK4mnonIOv9qV76i+nhmJIMaxqUeuzg9e7pF8=
 github.com/stateful/godotenv v0.0.0-20240309032207-c7bc0b812915/go.mod h1:A7pPuRB981nGoMyu09TOEDPHzg/eVlO3rgy1pk91xYY=
 github.com/stoewer/go-strcase v1.3.0 h1:g0eASXYtp+yvN9fK8sH94oCIk0fau9uV1/ZdJ0AVEzs=
@@ -290,8 +270,6 @@ github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
-github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/vektah/gqlparser/v2 v2.5.11 h1:JJxLtXIoN7+3x6MBdtIP59TP1RANnY7pXOaDnADQSf8=
 github.com/vektah/gqlparser/v2 v2.5.11/go.mod h1:1rCcfwB2ekJofmluGWXMSEnPMZgbxzwj6FaZ/4OT8Cc=
 github.com/xanzy/ssh-agent v0.3.3 h1:+/15pJfg/RsTxqYcX6fHqOXZwwMP+2VyYWJeWM2qQFM=
@@ -432,8 +410,6 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
-gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/warnings.v0 v0.1.2 h1:wFXVbFY8DY5/xOe1ECiWdKCzZlxgshcYVNkBHstARME=
 gopkg.in/warnings.v0 v0.1.2/go.mod h1:jksf8JmL6Qr/oQM2OXTHunEvvTAsrWBLb6OOjuVWRNI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

internal/cmd/beta/run_cmd.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/stateful/runme/v3/internal/command"
 	"github.com/stateful/runme/v3/internal/config/autoconfig"
-	"github.com/stateful/runme/v3/internal/document"
 	"github.com/stateful/runme/v3/internal/project"
 )
 
@@ -71,7 +70,7 @@ Run all blocks from the "setup" and "teardown" categories:
 					}
 
 					for _, t := range tasks {
-						err := runCodeBlock(t.CodeBlock, cmd, kernel, session, logger)
+						err := runCodeBlock(t, cmd, kernel, session, logger)
 						if err != nil {
 							return err
 						}
@@ -89,13 +88,23 @@ Run all blocks from the "setup" and "teardown" categories:
 }
 
 func runCodeBlock(
-	block *document.CodeBlock,
+	task project.Task,
 	cmd *cobra.Command,
 	kernel command.Kernel,
 	sess *command.Session,
 	logger *zap.Logger,
 ) error {
-	cfg, err := command.NewConfigFromCodeBlock(block)
+	// TODO(adamb): [command.Config] is generated exclusively from the [document.CodeBlock].
+	// As we introduce some document- and block-related configs in runme.yaml (root but also nested),
+	// this [Command.Config] should be further extended.
+	//
+	// The way to do it is to use [config.Loader] and calling [config.Loader.FindConfigChain] with
+	// task's document path. It will produce all the configs that are relevant to the document.
+	// Next, they should be merged into a single [config.Config] in a correct order, starting from
+	// the last element of the returned config chain. Finally, [command.Config] should be updated.
+	// This algorithm should be likely encapsulated in the [internal/config] and [internal/command]
+	// packages.
+	cfg, err := command.NewConfigFromCodeBlock(task.CodeBlock)
 	if err != nil {
 		return err
 	}

internal/config/autoconfig/autoconfig.go

@@ -8,19 +8,13 @@
 //	})
 //
 // Treat it as a dependency injection mechanism.
-//
-// autoconfig relies on [viper.Viper] which has a set of limitations. The most important one
-// is the fact that it does not support hierarchical configuration per folder. We might consider
-// switchig from [viper.Viper] to something else in the future.
 package autoconfig
 
 import (
 	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
-	"github.com/spf13/afero"
-	"github.com/spf13/viper"
 	"go.uber.org/dig"
 	"go.uber.org/multierr"
 	"go.uber.org/zap"
@@ -47,57 +41,21 @@ func mustProvide(err error) {
 }
 
 func init() {
-	// [viper.Viper] can be overridden by a decorator:
-	//   container.Decorate(func(v *viper.Viper) *viper.Viper { return nil })
-	mustProvide(container.Provide(getConfig))
+	mustProvide(container.Provide(getConfigLoader))
 	mustProvide(container.Provide(getKernelGetter))
 	mustProvide(container.Provide(getKernel))
 	mustProvide(container.Provide(getLogger))
 	mustProvide(container.Provide(getProject))
 	mustProvide(container.Provide(getProjectFilters))
+	mustProvide(container.Provide(getRootConfig))
 	mustProvide(container.Provide(getSession))
 	mustProvide(container.Provide(getUserConfigDir))
-	mustProvide(container.Provide(getViper))
-
-	if err := container.Invoke(func(viper *viper.Viper) {
-		viper.SetConfigName("runme")
-		viper.SetConfigType("yaml")
-
-		viper.AddConfigPath("/etc/runme/")
-		viper.AddConfigPath("$HOME/.runme/")
-		// TODO(adamb): change to "." when ready.
-		viper.AddConfigPath("experimental/")
-
-		viper.SetEnvPrefix("RUNME")
-		viper.AutomaticEnv()
-	}); err != nil {
-		panic("failed to setup configuration: " + err.Error())
-	}
 }
 
-func getConfig(userCfgDir UserConfigDir, viper *viper.Viper) (*config.Config, error) {
-	if err := viper.ReadInConfig(); err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	// As viper does not offer writing config to a writer,
-	// the workaround is to create a in-memory file system,
-	// set it in viper, and write the config to it.
-	// Finally, a deferred cleanup function is called
-	// which brings back the OS file system.
-	// Source: https://github.com/spf13/viper/issues/856
-	memFS := afero.NewMemMapFs()
-
-	viper.SetFs(memFS)
-	defer viper.SetFs(afero.NewOsFs())
-
-	if err := viper.WriteConfigAs("/config.yaml"); err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	content, err := afero.ReadFile(memFS, "/config.yaml")
+func getRootConfig(cfgLoader *config.Loader, userCfgDir UserConfigDir) (*config.Config, error) {
+	content, err := cfgLoader.RootConfig()
 	if err != nil {
-		return nil, errors.WithStack(err)
+		return nil, errors.WithMessage(err, "failed to load project configuration")
 	}
 
 	cfg, err := config.ParseYAML(content)
@@ -117,6 +75,12 @@ func getConfig(userCfgDir UserConfigDir, viper *viper.Viper) (*config.Config, er
 	return cfg, nil
 }
 
+func getConfigLoader() (*config.Loader, error) {
+	// TODO(adamb): change from "./experimental" to "." when the feature is stable and
+	// delete the project root path.
+	return config.NewLoader("runme", "yaml", os.DirFS("./experimental"), config.WithProjectRootPath(os.DirFS("."))), nil
+}
+
 func getKernel(c *config.Config, logger *zap.Logger) (_ command.Kernel, err error) {
 	// Find the first kernel that can be instantiated without error.
 	// This is inline with how the kernels are described in the configuration file.
@@ -329,5 +293,3 @@ func getUserConfigDir() (UserConfigDir, error) {
 	dir, err := os.UserConfigDir()
 	return UserConfigDir(dir), errors.WithStack(err)
 }
-
-func getViper() *viper.Viper { return viper.GetViper() }

internal/config/autoconfig/autoconfig_test.go

@@ -2,52 +2,33 @@ package autoconfig
 
 import (
 	"fmt"
-	"os"
-	"path/filepath"
 	"testing"
+	"testing/fstest"
 
-	"github.com/spf13/viper"
 	"github.com/stretchr/testify/require"
-	"go.uber.org/zap"
 
-	"github.com/stateful/runme/v3/internal/command"
 	"github.com/stateful/runme/v3/internal/config"
-	"github.com/stateful/runme/v3/internal/project"
 )
 
-func TestInvokeAll(t *testing.T) {
-	tempDir := t.TempDir()
-	readmeFilePath := filepath.Join(tempDir, "README.md")
-
-	// Create a README.md file in the temp directory.
-	err := os.WriteFile(readmeFilePath, []byte("Hello, World!"), 0o600)
-	require.NoError(t, err)
-
-	// Create a runme.yaml using the README.md file from above.
-	// This won't work with the project as it requires the project
-	// to be a subdirectory of the current working directory.
-	configYAML := fmt.Sprintf("version: v1alpha1\nfilename: %s\n", readmeFilePath)
-
-	// Create a runme.yaml file in the temp directory.
-	err = os.WriteFile(filepath.Join(tempDir, "/runme.yaml"), []byte(configYAML), 0o600)
-	require.NoError(t, err)
-	// And add it to the viper configuration.
-	// It's ok as viper has no other dependencies
-	// so nothing will be instantiated before
-	// the configuration is loaded.
-	err = Invoke(func(v *viper.Viper) {
-		v.AddConfigPath(tempDir)
+func TestInvokeConfig(t *testing.T) {
+	// Create fake filesystem and set it in the config loader.
+	fsys := fstest.MapFS{
+		"README.md": {
+			Data: []byte("Hello, World!"),
+		},
+		"runme.yaml": {
+			Data: []byte(fmt.Sprintf("version: v1alpha1\nfilename: %s\n", "README.md")),
+		},
+	}
+
+	err := Invoke(func(loader *config.Loader) error {
+		loader.SetConfigRootPath(fsys)
+		return nil
 	})
 	require.NoError(t, err)
 
-	// Load all dependencies.
 	err = Invoke(func(
 		*config.Config,
-		*zap.Logger,
-		*project.Project,
-		[]project.Filter,
-		*command.Session,
-		*viper.Viper,
 	) error {
 		return nil
 	})