First take

Author: bep

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: [1.16.x, 1.17.x]
+        go-version: [1.18.x, 1.19.x]
         os: [ubuntu-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:

README.md

@@ -1,2 +1,37 @@
-# gomaintemplate
-Just a simple main() Go program template.
+
+
+
+This is a simple Go program that finds the first `firstup.env` file starting from the current directory walking upwareds, excluding the root folder.
+
+It will write the env vars as export statements. It will also store the list of keys set in a separate environment variable and unset those next time `firstupdotenv` is run.
+
+The output may then look like this:
+
+```bash
+unset FOO
+unset BAR
+export FIRSTUPDOTENV_CURRENT_SET_ENV=FOO,BAR
+export FOO=value1
+export BAR=value2
+```
+
+The `.env` format is a file on the form  `key=value`. It ignores empty lines and lines starting with # and lines without an equals sign. If the same key is defined more than once, the last will win.
+
+To install:
+
+```bash
+go install github.com/bep/firstupdotenv@latest
+```
+
+This tool is meant to be used in combination with some shell extension that triggers when you `cd` into a directory. If you use the [Z shell](https://en.wikipedia.org/wiki/Z_shell), putting this in your `.zshrc` will work:
+
+```
+autoload -U add-zsh-hook
+
+firstupdotenv_after_cd() {
+	source <(firstupdotenv)
+}
+
+add-zsh-hook chpwd firstupdotenv_after_cd
+```
+

firstup.env

@@ -0,0 +1,3 @@
+# Test variables.
+FOO=value1
+BAR=value2

go.mod

@@ -1,13 +1,3 @@
-module github.com/bep/gomaintemplate
+module github.com/bep/firstupdotenv
 
 go 1.17
-
-require github.com/frankban/quicktest v1.14.2
-
-require (
-	github.com/google/go-cmp v0.5.7 // indirect
-	github.com/kr/pretty v0.3.0 // indirect
-	github.com/kr/text v0.2.0 // indirect
-	github.com/rogpeppe/go-internal v1.6.1 // indirect
-	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 // indirect
-)

go.sum

@@ -1,18 +0,0 @@
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
-github.com/frankban/quicktest v1.14.2 h1:SPb1KFFmM+ybpEjPUhCCkZOM5xlovT5UbrMvWnXyBns=
-github.com/frankban/quicktest v1.14.2/go.mod h1:mgiwOwqx65TmIk1wJ6Q7wvnVMocbUorkibMOrVTHZps=
-github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
-github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
-github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
-github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
-github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
-github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=

main.go

@@ -1,9 +1,135 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	name             = "firstupdotenv"
+	nameDotEnv       = "firstup.env"
+	currentSetEnvVar = "FIRSTUPDOTENV_CURRENT_SET_ENV"
 )
 
 func main() {
-	fmt.Println("Do something useful here...")
+	log.SetFlags(0)
+	log.SetPrefix(name + ": ")
+
+	env, err := createEnvSourceFromCurrentDir()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(env)
+}
+
+func createEnvSourceFromCurrentDir() (string, error) {
+	directory, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	var envSetScript strings.Builder
+
+	// Always remove the old settings, even if we don't find a new one.
+	old := os.Getenv(currentSetEnvVar)
+	if old != "" {
+		oldKeys := strings.Split(old, ",")
+		for _, key := range oldKeys {
+			envSetScript.WriteString(fmt.Sprintf("unset %s\n", key))
+		}
+	}
+
+	var envFromFile string
+
+	for {
+		if strings.Count(directory, string(os.PathSeparator)) < 2 {
+			// Stop before the root directory.
+			break
+		}
+
+		envFromFile, err = loadEnvFile(directory)
+		if err != nil {
+			return "", err
+		}
+
+		if envFromFile != "" {
+			break
+		}
+
+		// Walk up one directory.
+		directory = filepath.Dir(directory)
+	}
+
+	if envFromFile != "" {
+		envSetScript.WriteString(envFromFile)
+	} else {
+		envSetScript.WriteString(fmt.Sprintf("unset %s\n", currentSetEnvVar))
+	}
+
+	return envSetScript.String(), nil
+}
+
+func loadEnvFile(directory string) (string, error) {
+	filename := filepath.Join(directory, nameDotEnv)
+	if _, err := os.Stat(filename); err != nil {
+		return "", nil
+	}
+
+	envm, err := parseEnvFile(filename)
+	if err != nil {
+		return "", err
+	}
+	if len(envm) == 0 {
+		return "", nil
+	}
+
+	var envSetScript strings.Builder
+
+	var keys []string
+	for k, v := range envm {
+		os.Setenv(k, v)
+		keys = append(keys, k)
+	}
+	envSetScript.WriteString(fmt.Sprintf("export %s=%s\n", currentSetEnvVar, strings.Join(keys, ",")))
+
+	for k, v := range envm {
+		envSetScript.WriteString(fmt.Sprintf("export %s=%s\n", k, v))
+	}
+
+	return envSetScript.String(), nil
+
+}
+
+// parseEnvFile loads environment variables from text file on the form key=value.
+// It ignores empty lines and lines starting with # and lines without an equals sign.
+func parseEnvFile(filename string) (map[string]string, error) {
+	fi, err := os.Stat(filename)
+	if err != nil || fi.IsDir() {
+		return nil, nil
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	env := make(map[string]string)
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		key, value, found := strings.Cut(line, "=")
+		if !found {
+			continue
+		}
+		env[strings.TrimSpace(key)] = strings.TrimSpace(value)
+	}
+	return env, scanner.Err()
 }

main_test.go

@@ -1,15 +1,28 @@
 package main
 
 import (
+	"strings"
 	"testing"
-
-	qt "github.com/frankban/quicktest"
 )
 
-func TestFoo(t *testing.T) {
+func TestFindEnvInCurrentDir(t *testing.T) {
 	t.Parallel()
 
-	c := qt.New(t)
+	env, err := createEnvSourceFromCurrentDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	check := func(s ...string) {
+		for _, want := range s {
+			if !strings.Contains(env, want) {
+				t.Errorf("env %q does not contain %q", env, want)
+			}
+		}
+	}
+
+	check("export FIRSTUPDOTENV_CURRENT_SET_ENV=FOO,BAR")
+	check("export FOO=value1")
+	check("export BAR=value2")
 
-	c.Assert(true, qt.IsTrue)
 }