From bc65f33995e7aefc8a7817026f21800c5bd52bd6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Scott=20C=C3=B4t=C3=A9?= <scott.cote@hey.com>
Date: Tue, 5 Dec 2023 23:54:44 -0500
Subject: [PATCH] Add --once and --prefer

---
 .../__snapshots__/command.spec.ts.snap        |  6 ++-
 src/commands/sync.ts                          | 17 ++++++--
 src/services/filesync/filesync.ts             | 39 ++++++++++++++-----
 3 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/spec/services/command/__snapshots__/command.spec.ts.snap b/spec/services/command/__snapshots__/command.spec.ts.snap
index d7dba27b9..8244a2f08 100644
--- a/spec/services/command/__snapshots__/command.spec.ts.snap
+++ b/spec/services/command/__snapshots__/command.spec.ts.snap
@@ -52,8 +52,10 @@ ARGUMENTS
   DIRECTORY         The directory to sync files to (default: \\".\\")
 
 FLAGS
-  -a, --app=<name>  The Gadget application to sync files to
-      --force       Sync regardless of local file state
+  -a, --app=<name>             The Gadget application to sync files to
+      --prefer=<local|gadget>  Conflict resolution strategy
+      --once                   Sync once and exit
+      --force                  Sync regardless of local file state
 
 DESCRIPTION
   Sync allows you to synchronize your Gadget application's source
diff --git a/src/commands/sync.ts b/src/commands/sync.ts
index 75569a6e7..e2ee7f24a 100644
--- a/src/commands/sync.ts
+++ b/src/commands/sync.ts
@@ -10,7 +10,7 @@ import type { Command, Usage } from "../services/command/command.js";
 import { config } from "../services/config/config.js";
 import { Changes } from "../services/filesync/changes.js";
 import { YarnNotFoundError } from "../services/filesync/error.js";
-import { FileSync } from "../services/filesync/filesync.js";
+import { ConflictPreferenceArg, FileSync } from "../services/filesync/filesync.js";
 import { notify } from "../services/output/notify.js";
 import { reportErrorAndExit } from "../services/output/report.js";
 import { sprint } from "../services/output/sprint.js";
@@ -29,8 +29,10 @@ export const usage: Usage = () => sprint`
     DIRECTORY         The directory to sync files to (default: ".")
 
   {bold FLAGS}
-    -a, --app=<name>  The Gadget application to sync files to
-        --force       Sync regardless of local file state
+    -a, --app=<name>             The Gadget application to sync files to
+        --prefer=<local|gadget>  Conflict resolution strategy
+        --once                   Sync once and exit
+        --force                  Sync regardless of local file state
 
   {bold DESCRIPTION}
     Sync allows you to synchronize your Gadget application's source
@@ -91,6 +93,8 @@ export const usage: Usage = () => sprint`
 export const args = {
   "--app": { type: AppArg, alias: "-a" },
   "--force": Boolean,
+  "--once": Boolean,
+  "--prefer": ConflictPreferenceArg,
   "--file-push-delay": { type: Number, default: ms("100ms") },
   "--file-watch-debounce": { type: Number, default: ms("300ms") },
   "--file-watch-poll-interval": { type: Number, default: ms("3s") },
@@ -109,7 +113,12 @@ export const command: Command<typeof args> = async (ctx) => {
     force: ctx.args["--force"],
   });
 
-  await filesync.sync();
+  await filesync.sync({ preference: ctx.args["--prefer"] });
+
+  if (ctx.args["--once"]) {
+    ctx.log.println("Done!");
+    return;
+  }
 
   if (!which.sync("yarn", { nothrow: true })) {
     throw new YarnNotFoundError();
diff --git a/src/services/filesync/filesync.ts b/src/services/filesync/filesync.ts
index 76fd6df77..21be4f8c5 100644
--- a/src/services/filesync/filesync.ts
+++ b/src/services/filesync/filesync.ts
@@ -329,7 +329,7 @@ export class FileSync {
    *   local changes or keep Gadget's changes.
    * - This function will not return until the filesystem is in sync.
    */
-  async sync({ attempt = 0 }: { attempt?: number } = {}): Promise<void> {
+  async sync({ attempt = 0, preference }: { attempt?: number; preference?: ConflictPreference } = {}): Promise<void> {
     if (attempt > 10) {
       throw new TooManySyncAttemptsError(attempt);
     }
@@ -355,15 +355,18 @@ export class FileSync {
     const conflicts = getConflicts({ localChanges, gadgetChanges });
     if (conflicts.size > 0) {
       this.log.debug("conflicts detected", { conflicts });
-      printConflicts({
-        message: sprint`{bold You have conflicting changes with Gadget}`,
-        conflicts,
-      });
 
-      const preference = await select({
-        message: "How would you like to resolve these conflicts?",
-        choices: Object.values(ConflictPreference),
-      });
+      if (!preference) {
+        printConflicts({
+          message: sprint`{bold You have conflicting changes with Gadget}`,
+          conflicts,
+        });
+
+        preference = await select({
+          message: "How would you like to resolve these conflicts?",
+          choices: Object.values(ConflictPreference),
+        });
+      }
 
       switch (preference) {
         case ConflictPreference.CANCEL: {
@@ -392,7 +395,7 @@ export class FileSync {
     }
 
     // recursively call this function until we're in sync
-    return this.sync({ attempt: ++attempt });
+    return this.sync({ attempt: ++attempt, preference });
   }
 
   private async _getChangesFromGadget({
@@ -679,3 +682,19 @@ export const ConflictPreference = Object.freeze({
   LOCAL: "Keep my conflicting changes",
   GADGET: "Keep Gadget's conflicting changes",
 });
+
+export type ConflictPreference = (typeof ConflictPreference)[keyof typeof ConflictPreference];
+
+export const ConflictPreferenceArg = (value: string, name: string): ConflictPreference => {
+  if (["local", "gadget"].includes(value)) {
+    return ConflictPreference[value.toUpperCase() as keyof typeof ConflictPreference];
+  }
+
+  throw new ArgError(sprint`
+      ${name} must be {bold local} or {bold gadget}
+
+      {bold EXAMPLES:}
+        ${name} local
+        ${name} gadget
+    `);
+};