msgs

Overview ¶

Package msgs provides a simple event system for communication between different parts of the application. It is built on top of Wails' runtime event system but adds a layer for testability.

In production, events are emitted using Wails' runtime.EventsEmit. In test mode (enabled by calling SetTestMode(true)), events are dispatched to in-memory listeners. This allows tests to subscribe to events and wait for specific events to occur without relying on the Wails runtime.

Example Usage in Tests ¶

To use this package in tests for collections like AbisCollection, MonitorsCollection, or NamesCollection, you can use the WaitForLoadedEvent function to wait for the data to be loaded before making assertions.

First, ensure that test mode is enabled in your test setup:

```go

func TestMain(m *testing.M) {
 msgs.SetTestMode(true) // Enable test mode
 // It's also crucial to initialize the context if your code relies on it,
 // even in test mode, as some parts of the msgs package might still try to access it.
 // A background context is usually sufficient for tests.
 msgs.InitializeContext(context.Background())
 os.Exit(m.Run())
}

```

Then, in your test, you can create a collection, load data, and wait for the corresponding "loaded" event:

```go import (

"testing"
"time"

"github.com/TrueBlocks/trueblocks-dalledress/pkg/msgs"
"github.com/TrueBlocks/trueblocks-dalledress/pkg/types/abis" // or monitors, names
"github.com/stretchr/testify/assert"

)

func TestMyCollectionLoading(t *testing.T) {
 // Create a new collection (e.g., AbisCollection)
 abisCollection := abis.NewAbisCollection()

 // Start a goroutine to wait for the "Downloaded" abis to be loaded.
 // The string argument to WaitForLoadedEvent ("Downloaded", "Known", "Monitors", "All", etc.)
 // must match the 'facetName' or 'dataFacet' string used when msgs.EmitLoaded is called
 // by the collection's LoadData method.
 doneCh := msgs.WaitForLoadedEvent(string(abis.AbisDownloaded))

 // Trigger data loading
 abisCollection.FetchByFacet(abis.AbisDownloaded)

 // Wait for the data to be loaded, with a timeout
 select {
 case <-doneCh:
  // Data loaded, proceed with assertions
  page, err := abisCollection.GetPage(abis.AbisDownloaded, 0, 10, nil, "")
  assert.NoError(t, err)
  assert.NotNil(t, page)
  // Add more assertions as needed
 case <-time.After(5 * time.Second): // Adjust timeout as necessary
  t.Fatal("timed out waiting for abis to load")
 }
}

```

This pattern ensures that your tests are synchronized with the asynchronous data loading process.