From f5bbbcb572db7e8d87f01a29d71eb6bcf72992c4 Mon Sep 17 00:00:00 2001
From: Jean-Hadrien Chabran <jean-hadrien.chabran@sourcegraph.com>
Date: Wed, 3 Jul 2024 15:21:03 +0200
Subject: [PATCH] chore(local): sg warns about opposite default value on dev
 builds (#63612)

As I just reviewed a PR for `sg` about analytics, I've wasted 10m
wondering why I wasn't seeing anything (thought I might be on the wrong
branch, that type of things). Turned out, we obviously flip certain
default value for flags (such as disabling analytics) when running a dev
build.

`sg` now prints out a warning at the beginning stating which of those
are flipped out.

## Test plan

CI + local run

![CleanShot 2024-07-03 at 15 15
57@2x](https://github.com/sourcegraph/sourcegraph/assets/10151/5af2fb3d-eaa3-4503-804f-8336435a86f4)

Warning sign is missing, but it's there, something wrong with my font.

<!-- REQUIRED; info at
https://docs-legacy.sourcegraph.com/dev/background-information/testing_principles
-->

## Changelog

<!-- OPTIONAL; info at
https://www.notion.so/sourcegraph/Writing-a-changelog-entry-dd997f411d524caabf0d8d38a24a878c
-->
---
 dev/sg/main.go | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/dev/sg/main.go b/dev/sg/main.go
index 225e84a21ff..c4a1931f934 100644
--- a/dev/sg/main.go
+++ b/dev/sg/main.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	hashstructure "github.com/mitchellh/hashstructure/v2"
@@ -128,18 +129,18 @@ var sg = &cli.App{
 			Value:       false,
 			Destination: &disableOverwrite,
 		},
-		&cli.BoolFlag{
+		warnSkippedInDev(&cli.BoolFlag{
 			Name:    "skip-auto-update",
 			Usage:   "prevent sg from automatically updating itself",
 			EnvVars: []string{"SG_SKIP_AUTO_UPDATE"},
 			Value:   BuildCommit == "dev", // Default to skip in dev
-		},
-		&cli.BoolFlag{
+		}),
+		warnSkippedInDev(&cli.BoolFlag{
 			Name:    "disable-analytics",
 			Usage:   "disable event logging (logged to '~/.sourcegraph/events')",
 			EnvVars: []string{"SG_DISABLE_ANALYTICS"},
 			Value:   BuildCommit == "dev", // Default to skip in dev
-		},
+		}),
 		&cli.BoolFlag{
 			Name:        "disable-output-detection",
 			Usage:       "use fixed output configuration instead of detecting terminal capabilities",
@@ -178,6 +179,12 @@ var sg = &cli.App{
 		// Configure global output
 		std.Out = std.NewOutput(cmd.App.Writer, verbose)
 
+		// Print out a warning about flags which are disabled by default only in dev, but
+		// enabled otherwise.
+		if BuildCommit == "dev" {
+			printSkippedInDevWarning()
+		}
+
 		// Set up analytics and hooks for each command - do this as the first context
 		// setup
 		if !cmd.Bool("disable-analytics") {
@@ -424,6 +431,24 @@ func watchConfig(ctx context.Context) (<-chan *sgconf.Config, error) {
 	return output, err
 }
 
+var skippedInDevFlags = []cli.Flag{}
+
+// warnSkippedInDev registers a flag as having a different default value when sg is running in dev mode.
+func warnSkippedInDev(flag cli.Flag) cli.Flag {
+	skippedInDevFlags = append(skippedInDevFlags, flag)
+	return flag
+}
+
+// printSkippedInDevWarning reminds the user that sg is running in dev mode and certain flags have a different default value.
+func printSkippedInDevWarning() {
+	names := []string{}
+	for _, f := range skippedInDevFlags {
+		// Safe because it's not possible for a flag to not have name.
+		names = append(names, f.Names()[0])
+	}
+	std.Out.WriteWarningf("Running sg with a dev build, following flags have different default value unless explictly set: %s", strings.Join(names, ", "))
+}
+
 func exists(file string) bool {
 	_, err := os.Stat(file)
 	return !os.IsNotExist(err)