Add support for git-xargs registered environment variables based on arguments and flags

README.md

@@ -237,6 +237,16 @@ git-xargs --github-org my-github-org \
   "$(pwd)/scripts/my-ruby-script.rb"
 ```
 
+## Using `git-xargs` environment variables in commands or scripts
+
+When executing commands or scripts, `git-xargs` will register the following environment variables for use by commands or scripts based on the arguments and flags provided:
+
+| Env var            | Value
+| ------------------ | ---------------------------
+| `XARGS_DRY_RUN`    | Whether the `--dry-run` flag was provided to `git-xargs`; options are `true`, `false`
+| `XARGS_REPO_NAME`  | Name of the target repository being processed
+| `XARGS_REPO_OWNER` | Owner of the target repository being processed
+
 ## Debugging runtime errors
 
 By default, `git-xargs` will conceal runtime errors as they occur because its log level setting is `INFO` if not overridden by the `--loglevel` flag.

data/test/_testscripts/test-env-vars.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# This script writes some text to stdout and stderr and then exits.
+# This is used to test that git-xargs registers environment variables based on flags and arguments.
+
+echo "XARGS_DRY_RUN=$XARGS_DRY_RUN"
+echo "XARGS_REPO_NAME=$XARGS_REPO_NAME"
+echo "XARGS_REPO_OWNER=$XARGS_REPO_OWNER"

repository/repo-operations.go

@@ -110,6 +110,10 @@ func executeCommandWithLogger(config *config.GitXargsConfig, repositoryDir strin
 
 	cmd := exec.Command(cmdArgs[0], cmdArgs[1:]...)
 	cmd.Dir = repositoryDir
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, fmt.Sprintf("XARGS_DRY_RUN=%t", config.DryRun))
+	cmd.Env = append(cmd.Env, fmt.Sprintf("XARGS_REPO_NAME=%s", repo.GetName()))
+	cmd.Env = append(cmd.Env, fmt.Sprintf("XARGS_REPO_OWNER=%s", repo.GetOwner().GetLogin()))
 
 	logger.WithFields(logrus.Fields{
 		"Repo":      repo.GetName(),

repository/repo-operations_test.go

@@ -2,6 +2,7 @@ package repository
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 
 	"github.com/gruntwork-io/git-xargs/config"
@@ -50,3 +51,44 @@ func TestExecuteCommandWithLogger(t *testing.T) {
 	assert.Contains(t, buffer.String(), "Hello, from STDOUT")
 	assert.Contains(t, buffer.String(), "Hello, from STDERR")
 }
+
+// Test that we can execute a script and that the environment variables are set correctly.
+func TestExecuteCommandWithLoggerWithEnvVars(t *testing.T) {
+	t.Parallel()
+
+	cfg := config.NewGitXargsConfig()
+	cfg.Args = []string{"../data/test/_testscripts/test-env-vars.sh"}
+	repo := getMockGithubRepo()
+
+	var buffer bytes.Buffer
+
+	// Test whether the lack of --dry-run sets environment variable correctly
+	cfg.DryRun = false
+
+	logger := &logrus.Logger{
+		Out:       &buffer,
+		Level:     logrus.TraceLevel,
+		Formatter: new(logrus.TextFormatter),
+	}
+
+	err := executeCommandWithLogger(cfg, ".", repo, logger)
+	assert.NoError(t, err)
+	assert.Contains(t, buffer.String(), "XARGS_DRY_RUN=false")
+	assert.Contains(t, buffer.String(), fmt.Sprintf("XARGS_REPO_NAME=%s", *repo.Name))
+	assert.Contains(t, buffer.String(), fmt.Sprintf("XARGS_REPO_OWNER=%s", *repo.Owner.Login))
+
+	// Test whether --dry-run sets environment variable correctly
+	cfg.DryRun = true
+
+	logger = &logrus.Logger{
+		Out:       &buffer,
+		Level:     logrus.TraceLevel,
+		Formatter: new(logrus.TextFormatter),
+	}
+
+	err = executeCommandWithLogger(cfg, ".", repo, logger)
+	assert.NoError(t, err)
+	assert.Contains(t, buffer.String(), "XARGS_DRY_RUN=true")
+	assert.Contains(t, buffer.String(), fmt.Sprintf("XARGS_REPO_NAME=%s", *repo.Name))
+	assert.Contains(t, buffer.String(), fmt.Sprintf("XARGS_REPO_OWNER=%s", *repo.Owner.Login))
+}