fix(MOB-225): make native deploy outcomes honest

AGENTS.md

@@ -250,7 +250,10 @@ should know:
 
 - **`mix mob.install`** — first-run **project setup**. Downloads the
   OTP runtime, generates icons, writes `mob.exs`. Per-project, runs
-  once. Doesn't touch any device.
+  once. Doesn't touch any device. A later `mix mob.deploy --native` also
+  repairs or creates `android/local.properties` when it can detect the SDK;
+  fresh worktrees therefore do not need another interactive install just to
+  restore that gitignored machine-local file.
 - **`mix mob.uninstall`** — per-**device** app removal. Sweeps
   connected devices and removes installed `.app` / `.apk` bundles.
   Doesn't undo `mix mob.install`'s project setup.

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 ### Fixed
 
+- **`mix mob.deploy --native --device <id>` can no longer report success after
+  skipping the named device's native build** (MOB-225). The selected device now
+  makes its platform a required build target even without a redundant
+  `--android` / `--ios` flag. Android native deploys also create the gitignored
+  `android/local.properties` when the SDK is detectable, sharing
+  `mix mob.install`'s path writer; when it is not detectable, the skipped
+  requested build exits non-zero.
+
 - **`mix mob.connect --name` is now honored end-to-end** (MOB-69). The
   option was parsed at the task layer, but `Connector.connect_all/1`
   called `ensure_local_dist/1` which hardcoded `Node.start(:"mob_dev@127.0.0.1", ...)`.

README.md

@@ -145,10 +145,12 @@ unloaded at any moment.
 - every selected device of a platform you **named** was skipped —
   `mix mob.deploy --ios --device <id>` where the target lacked the app;
 - you named `--device X` and nothing was deployed to it, or no device matched;
-- `--native` built nothing for a platform you **named** — a missing `sdk.dir`
-  in `android/local.properties` under `--android --native`, say. A plain
-  `mix mob.deploy --native` that skips a platform nobody asked for still
-  exits 0;
+- `--native` built nothing for a platform you **named**, directly or through
+  `--device` — a non-detectable Android SDK under either
+  `--android --native` or `--native --device <android-id>`, say. When the SDK
+  is detectable, deploy creates the gitignored `android/local.properties`
+  automatically. A plain `mix mob.deploy --native` that skips a platform
+  nobody asked for still exits 0;
 - you selected a broad scope and no device matched it. Naming a platform alone
   still permits a native artifact-only build with no attached device.
 

lib/mix/tasks/mob.deploy.ex

@@ -127,6 +127,12 @@ defmodule Mix.Tasks.Mob.Deploy do
       xcodebuild -scheme <app> -destination 'platform=iOS Simulator,...' build
       xcrun simctl install booted <app>.app
 
+  A named `--device` supplies the platform when `--native` is used, so
+  `mix mob.deploy --native --device <id>` does not also need `--android` or
+  `--ios`. Before an Android build, the task creates
+  `android/local.properties` when the SDK is detectable, just as
+  `mix mob.install` does during first-run setup.
+
   ## Exit status
 
   Every targeted device is attempted and the full summary printed, then the
@@ -148,8 +154,10 @@ defmodule Mix.Tasks.Mob.Deploy do
     * `mix mob.deploy --android --native` that built the APK with no device
       attached — exit 0. The artifact is what was asked for.
 
-  `--native` fails the run when a platform you named built nothing at all, which
-  is what a missing `sdk.dir` in `android/local.properties` produces.
+  `--native` fails the run when a platform you named — directly or through
+  `--device` — built nothing at all. If the Android SDK cannot be detected,
+  a missing `sdk.dir` therefore produces a non-zero exit instead of a warning
+  followed by success.
   """
 
   alias MobDev.{Device, TaskTargets}
@@ -256,7 +264,7 @@ defmodule Mix.Tasks.Mob.Deploy do
     # the build platforms to it when devices exist, then pass the same structs
     # through compatibility checks, native installation, and the final push.
     platforms = selected_platforms(platforms, devices)
-    required_platforms = required_platforms(opts, platforms)
+    required_platforms = required_platforms(opts, platforms, target_reference)
     beam_flags = resolve_beam_flags(opts)
 
     # Validate every targeted device against the project's enabled
@@ -300,6 +308,13 @@ defmodule Mix.Tasks.Mob.Deploy do
 
     native_ok =
       if native do
+        if :android in platforms do
+          Mix.Tasks.Mob.Install.write_local_properties(
+            File.cwd!(),
+            MobDev.Config.load_mob_config()
+          )
+        end
+
         MobDev.NativeBuild.build_all(
           platforms: platforms,
           devices: devices,
@@ -663,13 +678,27 @@ defmodule Mix.Tasks.Mob.Deploy do
   end
 
   @doc false
-  @spec required_platforms(keyword(), [:android | :ios]) :: [:android | :ios]
-  def required_platforms(opts, selected_platforms) do
+  @spec required_platforms(
+          keyword(),
+          [:android | :ios],
+          String.t() | {:device | :android_serial, String.t()} | nil
+        ) :: [:android | :ios]
+  def required_platforms(opts, selected_platforms, target_reference \\ nil) do
     requested = requested_platforms(opts)
 
-    if requested == [] and (opts[:all_devices] == true or opts[:all_physical] == true),
-      do: selected_platforms,
-      else: requested
+    cond do
+      requested != [] ->
+        requested
+
+      opts[:all_devices] == true or opts[:all_physical] == true ->
+        selected_platforms
+
+      opts[:native] == true and target_reference != nil ->
+        selected_platforms
+
+      true ->
+        []
+    end
   end
 
   @doc false

lib/mix/tasks/mob.install.ex

@@ -295,33 +295,63 @@ defmodule Mix.Tasks.Mob.Install do
   @doc false
   @spec write_local_properties(String.t(), keyword()) :: :ok | nil
   def write_local_properties(project_dir, cfg) do
-    props = Path.join(project_dir, "android/local.properties")
+    write_local_properties(project_dir, cfg, detect_android_sdk())
+  end
 
-    if File.exists?(props) do
-      content = File.read!(props)
+  @doc false
+  @spec write_local_properties(String.t(), keyword(), String.t() | nil) :: :ok | nil
+  def write_local_properties(project_dir, cfg, detected_sdk) do
+    props = Path.join(project_dir, "android/local.properties")
 
-      needs_mob_paths? = String.contains?(content, "/path/to/")
-      needs_sdk_dir? = not has_active_sdk_dir?(content)
+    cond do
+      File.exists?(props) ->
+        content = File.read!(props)
 
-      if needs_mob_paths? or needs_sdk_dir? do
-        otp_dir = MobDev.OtpDownloader.android_otp_dir("arm64-v8a")
-        otp_dir_arm32 = MobDev.OtpDownloader.android_otp_dir("armeabi-v7a")
-        otp_dir_x86_64 = MobDev.OtpDownloader.android_otp_dir("x86_64")
+        needs_mob_paths? = String.contains?(content, "/path/to/")
+        needs_sdk_dir? = not has_active_sdk_dir?(content)
 
-        new_content =
-          content
-          |> replace_prop("mob.otp_release", otp_dir)
-          |> replace_prop("mob.otp_release_arm32", otp_dir_arm32)
-          |> replace_prop("mob.otp_release_x86_64", otp_dir_x86_64)
-          |> replace_prop("mob.mob_dir", cfg[:mob_dir])
-          |> ensure_sdk_dir(detect_android_sdk())
+        if needs_mob_paths? or needs_sdk_dir? do
+          new_content = configure_local_properties(content, cfg, detected_sdk)
+          File.write!(props, new_content)
+          Mix.shell().info([:green, "* android/local.properties configured", :reset])
+        end
 
-        File.write!(props, new_content)
+      File.dir?(Path.join(project_dir, "android")) and is_binary(detected_sdk) ->
+        content = configure_local_properties(local_properties_template(), cfg, detected_sdk)
+        File.write!(props, content)
         Mix.shell().info([:green, "* android/local.properties configured", :reset])
-      end
+
+      true ->
+        nil
     end
   end
 
+  defp configure_local_properties(content, cfg, detected_sdk) do
+    content
+    |> replace_prop("mob.otp_release", MobDev.OtpDownloader.android_otp_dir("arm64-v8a"))
+    |> replace_prop(
+      "mob.otp_release_arm32",
+      MobDev.OtpDownloader.android_otp_dir("armeabi-v7a")
+    )
+    |> replace_prop(
+      "mob.otp_release_x86_64",
+      MobDev.OtpDownloader.android_otp_dir("x86_64")
+    )
+    |> replace_prop("mob.mob_dir", cfg[:mob_dir])
+    |> ensure_sdk_dir(detected_sdk)
+  end
+
+  defp local_properties_template do
+    """
+    # Machine-local Android and Mob paths. Generated by mix mob.install or mix mob.deploy.
+    # sdk.dir=/path/to/android/sdk
+    mob.otp_release=/path/to/otp
+    mob.otp_release_arm32=/path/to/otp-arm32
+    mob.otp_release_x86_64=/path/to/otp-x86_64
+    mob.mob_dir=/path/to/mob
+    """
+  end
+
   # Returns true iff local.properties has an *uncommented* `sdk.dir=...` line.
   # The mob_new template ships with a commented `# sdk.dir=...` placeholder; we
   # treat that as "not set" so the auto-detection writes a real value over it.

lib/mob_dev/native_build.ex

@@ -210,14 +210,17 @@ defmodule MobDev.NativeBuild do
   `results` entries are `{:ok, label}` / `{:error, label, reason}` where label
   is the display name ("Android", "iOS", "iOS (device)").
 
-  `requested` is the platforms named by an explicit `--android` / `--ios`
-  flag — NOT the resolved platform list, which collapses "no flag given" into
-  every platform and would make an ordinary skip fatal.
+  `requested` is the platforms required by an explicit `--android` / `--ios`
+  flag, broad target scope, or named `--device` under `--native` — NOT the
+  complete resolved platform list, which collapses "no flag given" into every
+  platform and would make an ordinary skip fatal.
 
   The rule this exists for: `ok_count == length(results)` is `0 == 0` for a run
   that built nothing, so `mix mob.deploy --android --native` with no `sdk.dir`
-  printed a warning, built nothing, and reported success. A skip is fine when
-  nobody asked for that platform; it is a failure when they did.
+  printed a warning, built nothing, and reported success. The same failure
+  occurred for `--native --device <android-id>` because the device-resolved
+  platform was not considered requested. A skip is fine when nobody asked for
+  that platform; it is a failure when they did.
   """
   @spec build_outcome([{:ok, String.t()} | {:error, String.t(), term()}], [atom()]) ::
           :ok | {:error, String.t()}

test/mix/tasks/mob_deploy_parsing_test.exs

@@ -169,6 +169,24 @@ defmodule Mix.Tasks.Mob.DeployParsingTest do
       assert Deploy.required_platforms([ios: true], [:ios]) == [:ios]
       assert Deploy.required_platforms([], [:android]) == []
     end
+
+    test "--native makes the named device platform a required build" do
+      assert Deploy.required_platforms(
+               [native: true, device: "ZY22K6BSJM"],
+               [:android],
+               {:device, "ZY22K6BSJM"}
+             ) == [:android]
+
+      assert Deploy.required_platforms(
+               [native: true, device: "SIM-UDID"],
+               [:ios],
+               {:device, "SIM-UDID"}
+             ) == [:ios]
+    end
+
+    test "a bare --native artifact build does not require every scaffolded platform" do
+      assert Deploy.required_platforms([native: true], [:android, :ios], nil) == []
+    end
   end
 
   describe "what it still refuses" do

test/mix/tasks/mob_install_test.exs

@@ -102,8 +102,20 @@ defmodule Mix.Tasks.Mob.InstallTest do
       assert File.read!(props_path(dir)) == original
     end
 
-    test "does nothing when local.properties does not exist", %{dir: dir} do
-      Install.write_local_properties(dir, mob_dir: dir)
+    test "creates local.properties when the Android SDK is detectable", %{dir: dir} do
+      sdk = Path.join(dir, "android-sdk")
+      File.mkdir_p!(sdk)
+
+      Install.write_local_properties(dir, [mob_dir: dir], sdk)
+
+      content = File.read!(props_path(dir))
+      assert content =~ "sdk.dir=#{sdk}"
+      assert content =~ "mob.otp_release=#{OtpDownloader.android_otp_dir("arm64-v8a")}"
+      assert content =~ "mob.mob_dir=#{dir}"
+    end
+
+    test "does not create local.properties when no Android SDK is detectable", %{dir: dir} do
+      Install.write_local_properties(dir, [mob_dir: dir], nil)
       refute File.exists?(props_path(dir))
     end
   end

test/mob_dev/wiring_test.exs

@@ -134,6 +134,20 @@ defmodule MobDev.WiringTest do
       body = region(@deploy_task, "MobDev.NativeBuild.build_all(", "\n        )")
 
       assert body =~ "requested: required_platforms"
+
+      assert @deploy_task =~
+               "required_platforms(opts, platforms, target_reference)"
+    end
+
+    test "the task prepares only Android local.properties before checking the toolchain" do
+      prepare_at = index_of(@deploy_task, "Mix.Tasks.Mob.Install.write_local_properties(")
+      build_at = index_of(@deploy_task, "MobDev.NativeBuild.build_all(")
+      native_build = region(@deploy_task, "native_ok =", "MobDev.NativeBuild.build_all(")
+
+      assert prepare_at < build_at
+      assert prepare_at > 0
+      assert native_build =~ "if :android in platforms do"
+      assert native_build =~ "Mix.Tasks.Mob.Install.write_local_properties("
     end
 
     test "the build reads that back and runs it through build_outcome/2" do