initial commit
This commit is contained in:
commit
cfd661ceb4
2 changed files with 397 additions and 0 deletions
84
config.go
Normal file
84
config.go
Normal file
|
|
@ -0,0 +1,84 @@
|
|||
// Package config defines utils to simplify configuration
|
||||
// management
|
||||
package conf
|
||||
|
||||
import (
|
||||
"encoding/json"
|
||||
"fmt"
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"path/filepath"
|
||||
)
|
||||
|
||||
// LoadFile reads the file at path, parses its json content and fills the struct
|
||||
// with the content of the file.
|
||||
func LoadFile(path string, data interface{}) error {
|
||||
return read(path, data)
|
||||
}
|
||||
|
||||
// SaveFile writes the given data serialized in JSON in the given path
|
||||
func SaveFile(path string, data interface{}) error {
|
||||
return write(path, data)
|
||||
}
|
||||
|
||||
// LoadAndUpdateFile reads the config fileat path and
|
||||
// updates it, meaning that it adds new options, removes
|
||||
// old ones, and update it by calling the Update method of
|
||||
// data if it implements the interface Updater.
|
||||
//
|
||||
// If no file is found at path, it is created and
|
||||
// initialized with the default values.
|
||||
//
|
||||
// An error is returned only if the config file cannot be
|
||||
// written.
|
||||
func LoadAndUpdateFile(path string, data interface{}) error {
|
||||
if _, err := os.Stat(path); !os.IsNotExist(err) {
|
||||
err2 := read(path, data)
|
||||
if err2 != nil {
|
||||
return err2
|
||||
}
|
||||
|
||||
if data, ok := data.(Updater); ok {
|
||||
data.Update()
|
||||
}
|
||||
}
|
||||
|
||||
return write(path, data)
|
||||
}
|
||||
|
||||
// Updater is the interface that can be implemented by
|
||||
// config structs. If it is implemented, Update() is
|
||||
// called by LoadAndUpdateFile(). It allows one to modify
|
||||
// the data and persist those changes, for example to
|
||||
// change default values
|
||||
type Updater interface {
|
||||
Update()
|
||||
}
|
||||
|
||||
func read(path string, data interface{}) error {
|
||||
content, err := ioutil.ReadFile(filepath.Clean(path))
|
||||
if err != nil {
|
||||
return fmt.Errorf("cannot read config file: %w", err)
|
||||
}
|
||||
|
||||
err = json.Unmarshal(content, &data)
|
||||
if err != nil {
|
||||
return fmt.Errorf("cannot parse config file: %w", err)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
func write(path string, data interface{}) error {
|
||||
content, err := json.MarshalIndent(data, "", " ")
|
||||
if err != nil {
|
||||
return fmt.Errorf("cannot generate config content: %w", err)
|
||||
}
|
||||
|
||||
err = ioutil.WriteFile(path, content, 0644)
|
||||
if err != nil {
|
||||
return fmt.Errorf("cannot write config file '%s': %w", path, err)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
313
config_test.go
Normal file
313
config_test.go
Normal file
|
|
@ -0,0 +1,313 @@
|
|||
package conf
|
||||
|
||||
import (
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"testing"
|
||||
|
||||
. "github.com/smartystreets/goconvey/convey"
|
||||
)
|
||||
|
||||
type testconf struct {
|
||||
String string
|
||||
Int int
|
||||
Invariant string
|
||||
inUpdate func()
|
||||
}
|
||||
|
||||
func (t testconf) Update() {
|
||||
if t.inUpdate != nil {
|
||||
t.inUpdate()
|
||||
}
|
||||
}
|
||||
|
||||
func TestLoadFile(t *testing.T) {
|
||||
Convey("Given a config struct", t, func() {
|
||||
c := testconf{
|
||||
String: "default string",
|
||||
Int: 1,
|
||||
Invariant: "should not change",
|
||||
}
|
||||
|
||||
Convey("Given a valid config file", func() {
|
||||
file := "test.conf"
|
||||
content := []byte(`{"String": "config string", "Int": 42}`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When the config file is loaded", func() {
|
||||
err := LoadFile(file, &c)
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the struct fields are filled", func() {
|
||||
So(c.String, ShouldEqual, "config string")
|
||||
So(c.Int, ShouldEqual, 42)
|
||||
})
|
||||
|
||||
Convey("Then the default values are kept", func() {
|
||||
So(c.Invariant, ShouldEqual, "should not change")
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given an invalid config file", func() {
|
||||
file := "test.conf"
|
||||
content := []byte(`String: not json`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When the config file is loaded", func() {
|
||||
err := LoadFile(file, &c)
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
|
||||
Convey("Then the struct fields are not filled", func() {
|
||||
So(c.String, ShouldEqual, "default string")
|
||||
So(c.Int, ShouldEqual, 1)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given a non existent config file", func() {
|
||||
file := "does-not-exist.conf.conf"
|
||||
|
||||
Convey("When the config file is loaded", func() {
|
||||
err := LoadFile(file, &c)
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
|
||||
Convey("Then the struct fields are not filled", func() {
|
||||
So(c.String, ShouldEqual, "default string")
|
||||
So(c.Int, ShouldEqual, 1)
|
||||
})
|
||||
})
|
||||
})
|
||||
})
|
||||
}
|
||||
|
||||
func TestSaveFile(t *testing.T) {
|
||||
Convey("Given a config struct", t, func() {
|
||||
c := testconf{
|
||||
String: "default string",
|
||||
Int: 1,
|
||||
Invariant: "should not change",
|
||||
}
|
||||
|
||||
Convey("Given a valid path", func() {
|
||||
file := "test.conf"
|
||||
|
||||
Convey("When the config file is saved", func() {
|
||||
err := SaveFile(file, &c)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the file exists", func() {
|
||||
_, err := os.Stat(file)
|
||||
So(err, ShouldBeNil)
|
||||
|
||||
Convey("Then the content is correct", func() {
|
||||
expected := "{\n \"String\": \"default string\",\n \"Int\": 1,\n \"Invariant\": \"should not change\"\n}"
|
||||
got, err := ioutil.ReadFile(file)
|
||||
So(err, ShouldBeNil)
|
||||
So(string(got), ShouldEqual, expected)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("When the config file is saved with invalid data", func() {
|
||||
err := SaveFile(file, func() error { return nil })
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
|
||||
Convey("Then the file does not exist", func() {
|
||||
_, err := os.Stat(file)
|
||||
So(os.IsNotExist(err), ShouldBeTrue)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given an invalid path", func() {
|
||||
file := "cannot/write/here.conf"
|
||||
|
||||
Convey("When the config file is loaded", func() {
|
||||
err := SaveFile(file, &c)
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
|
||||
Convey("Then the file does not exist", func() {
|
||||
_, err := os.Stat(file)
|
||||
So(os.IsNotExist(err), ShouldBeTrue)
|
||||
})
|
||||
})
|
||||
})
|
||||
})
|
||||
}
|
||||
|
||||
func TestLoadAndUpdateFile(t *testing.T) {
|
||||
Convey("Given a config struct and a path", t, func() {
|
||||
updated := false
|
||||
|
||||
c := testconf{
|
||||
String: "default string",
|
||||
Int: 1,
|
||||
Invariant: "should not change",
|
||||
}
|
||||
c.inUpdate = func() { updated = true }
|
||||
file := "test.conf"
|
||||
|
||||
Convey("Given no file exists at this path", func() {
|
||||
_, err := os.Stat(file)
|
||||
So(err, ShouldBeError)
|
||||
So(os.IsNotExist(err), ShouldBeTrue)
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("Then the config file has been created", func() {
|
||||
_, err := os.Stat(file)
|
||||
So(err, ShouldBeNil)
|
||||
|
||||
Convey("and it has the default configuration", func() {
|
||||
var c2 testconf
|
||||
err := read(file, &c2)
|
||||
So(err, ShouldBeNil)
|
||||
c.inUpdate = nil
|
||||
So(c2, ShouldResemble, c)
|
||||
})
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given the path cannot be written", func() {
|
||||
file = "does-not-exist/test.conf"
|
||||
_, err := os.Stat(file)
|
||||
So(err, ShouldBeError)
|
||||
So(os.IsNotExist(err), ShouldBeTrue)
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given a config file with custom values", func() {
|
||||
content := []byte(`{"String": "config string", "Int": 42}`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the struct fields are filled", func() {
|
||||
So(c.String, ShouldEqual, "config string")
|
||||
So(c.Int, ShouldEqual, 42)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given an invalid configuration file", func() {
|
||||
content := []byte(`String: not json`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("Then an error is returned", func() {
|
||||
So(err, ShouldBeError)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given a config file with missing options", func() {
|
||||
content := []byte(`{"String": "config string"}`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the config file has been updated with new options", func() {
|
||||
content, err := ioutil.ReadFile(file)
|
||||
So(err, ShouldBeNil)
|
||||
So(string(content), ShouldContainSubstring, `"Int"`)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given a config file with old options", func() {
|
||||
content := []byte(`{"String": "config string", "Foo": "blah"}`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the config file has been updated with new options", func() {
|
||||
content, err := ioutil.ReadFile(file)
|
||||
So(err, ShouldBeNil)
|
||||
So(string(content), ShouldNotContainSubstring, `"Foo"`)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
Convey("Given a valid config file", func() {
|
||||
content := []byte(`{"String": "config string"}`)
|
||||
err := ioutil.WriteFile(file, content, 0o644)
|
||||
So(err, ShouldBeNil)
|
||||
defer func() { _ = os.Remove(file) }()
|
||||
|
||||
Convey("When LoadAndUpdateFile is called", func() {
|
||||
err := LoadAndUpdateFile(file, &c)
|
||||
|
||||
Convey("Then there is no error", func() {
|
||||
So(err, ShouldBeNil)
|
||||
})
|
||||
|
||||
Convey("Then the update method of the struct has been called", func() {
|
||||
So(updated, ShouldBeTrue)
|
||||
})
|
||||
})
|
||||
})
|
||||
})
|
||||
}
|
||||
Loading…
Reference in a new issue