Make atomvm_pico_flash_provider easier to test

Add some more verbose logging (when in test mode) to give test the ability to parse parameters sent
to picotool. Reduces times waiting for mount points, since we are not waiting for real hardware to
settle. Allows the use of a mock esptool for testing under CI or when no RP2 hardware is present.

Signed-off-by: Winford <winford@object.stream>

Author: UncleGrumpy

src/atomvm_pico_flash_provider.erl

@@ -119,11 +119,17 @@ env_opts() ->
 
 %% @private
 find_picotool() ->
-    case os:find_executable("picotool") of
-        false ->
-            "";
-        Picotool ->
-            Picotool
+    %% We use a mock picotool for CI tests to simulate resetting and mounting a device.
+    case os:getenv("ATOMVM_REBAR3_TEST_MODE") of
+        "true" ->
+            os:getenv("ATOMVM_REBAR3_TEST_PICOTOOL");
+        _ ->
+            case os:find_executable("picotool") of
+                false ->
+                    "";
+                Picotool ->
+                    Picotool
+            end
     end.
 
 %% @private
@@ -201,12 +207,19 @@ wait_for_mount(_Mount, 30) ->
 
 %% @private
 get_pico_mount(Mount) ->
+    Count =
+        case os:getenv("ATOMVM_REBAR3_TEST_MODE") of
+            "true" ->
+                25;
+            _ ->
+                0
+        end,
     case Mount of
         "" ->
             case find_mounted_pico() of
                 not_found ->
                     rebar_api:info("Waiting for an RP2 device to mount...", []),
-                    wait_for_mount(Mount, 0);
+                    wait_for_mount(Mount, Count);
                 {ok, Pico} ->
                     {ok, Pico}
             end;
@@ -219,7 +232,7 @@ get_pico_mount(Mount) ->
                     rebar_api:info("Waiting for the device at path ~s to mount...", [
                         string:trim(Mount)
                     ]),
-                    wait_for_mount(Mount, 0)
+                    wait_for_mount(Mount, Count)
             end
     end.
 
@@ -270,7 +283,12 @@ do_reset(ResetPort, Picotool) ->
                     rebar_api:warn("Disconnecting serial monitor with: `~s' in 5 seconds...", [
                         DevReset
                     ]),
-                    timer:sleep(5000),
+                    case os:getenv("ATOMVM_REBAR3_TEST_MODE") of
+                        "true" ->
+                            ok;
+                        _ ->
+                            timer:sleep(5000)
+                    end,
                     RebootReturn = os:cmd(DevReset),
                     RebootStatus = string:trim(RebootReturn),
                     case RebootStatus of
@@ -297,6 +315,16 @@ get_uf2_appname(ProjectApps) ->
 
 %% @private
 do_flash(ProjectApps, PicoPath, ResetDev, Picotool) ->
+    TestMode = os:getenv("ATOMVM_REBAR3_TEST_MODE"),
+    case TestMode of
+        "true" ->
+            rebar_api:info(
+                "Using picotool options:~n  --path ~s~n  --reset ~s~n  --picotool ~s",
+                [PicoPath, ResetDev, Picotool]
+            );
+        _ ->
+            ok
+    end,
     case needs_reset(ResetDev) of
         false ->
             rebar_api:debug("No Pico reset device found matching ~s.", [ResetDev]),
@@ -305,7 +333,15 @@ do_flash(ProjectApps, PicoPath, ResetDev, Picotool) ->
             rebar_api:debug("Pico at ~s needs reset...", [ResetPort]),
             do_reset(ResetPort, Picotool),
             rebar_api:info("Waiting for the device at path ~s to settle and mount...", [PicoPath]),
-            wait_for_mount(PicoPath, 0)
+            %% Reduce the timeout for tests since we aren't waiting for real hardware
+            Count =
+                case TestMode of
+                    "true" ->
+                        25;
+                    _ ->
+                        0
+                end,
+            wait_for_mount(PicoPath, Count)
     end,
     {ok, Path} = get_pico_mount(PicoPath),
     TargetUF2 = get_uf2_file(ProjectApps),