feat: use typed events (#1030)

- [x] switch to typed event for `blob` module'
- [ ] ~~Refactor integration test~~
- [x] Closes #968

proto/blob/event.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+package blob;
+
+import "gogoproto/gogo.proto";
+
+option go_package = "github.com/celestiaorg/celestia-app/x/blob/types";
+
+// EventPayForBlob defines an event that is emitted with the signer and blob size
+// at the end of a pay for blob txn
+message EventPayForBlob {
+  string signer = 1;
+  uint64 blob_size = 2;
+}

x/blob/README.md

@@ -29,14 +29,23 @@ The malleation process occurs during the PrepareProposal step.
 
 ## Events
 
-- [`NewPayForBlobEvent`](https://github.com/celestiaorg/celestia-app/pull/213/files#diff-1ce55bda42cf160deca2e5ea1f4382b65f3b689c7e00c88085d7ce219e77303dR17-R21) is emitted with the signer's address and size of the blob that is paid for.
+The blob module emits the following events:
+
+### Blob Events
+
+#### EventPayForBlob
+
+| Attribute Key | Attribute Value                 |
+|---------------|---------------------------------|
+| signer        | {bech32 encoded signer address} |
+| blob_size     | {size in bytes}                 |
 
 ## Parameters
 
-Key | Type | Example
---- | --- | ---
-MinSquareSize | uint32 | 1
-MaxSquareSize | uint32 | 128
+| Key           | Type   | Example |
+|---------------|--------|---------|
+| MinSquareSize | uint32 | 1       |
+| MaxSquareSize | uint32 | 128     |
 
 ### Usage
 

x/blob/keeper/keeper.go

@@ -61,9 +61,12 @@ func (k Keeper) PayForBlob(goCtx context.Context, msg *types.MsgPayForBlob) (*ty
 	gasToConsume := uint64(shares.BlobSharesUsed(int(msg.BlobSize)) * GasPerBlobShare)
 	ctx.GasMeter().ConsumeGas(gasToConsume, payForBlobGasDescriptor)
 
-	ctx.EventManager().EmitEvent(
+	err := ctx.EventManager().EmitTypedEvent(
 		types.NewPayForBlobEvent(sdk.AccAddress(msg.Signer).String(), msg.GetBlobSize()),
 	)
+	if err != nil {
+		return &types.MsgPayForBlobResponse{}, err
+	}
 
 	return &types.MsgPayForBlobResponse{}, nil
 }