From 713bbdd60cbb6dbc2b7c3803d2ab344a46b340bd Mon Sep 17 00:00:00 2001
From: Jim McDonald <Jim@mcdee.net>
Date: Tue, 13 Jun 2023 00:22:32 +0100
Subject: [PATCH] Add epoch parameter to validator yield.

---
 CHANGELOG.md                   |  3 ++-
 cmd/validator/yield/command.go |  4 +++-
 cmd/validator/yield/process.go | 16 ++++++++++------
 cmd/validatoryield.go          |  4 ++++
 docs/usage.md                  |  1 +
 5 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 574a314..efe0cc4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,8 @@
 dev:
   - fix incorrect error when "deposit veirfy" is not given a withdrawal address
   - allow truncated mnemonics (first four characters of each word)
-  - add deneb informatoin to "block info"
+  - add deneb information to "block info"
+  - add epoch parameter to "validator yield"
 
 1.31.0:
   - initial support for deneb
diff --git a/cmd/validator/yield/command.go b/cmd/validator/yield/command.go
index 3678b76..22418c1 100644
--- a/cmd/validator/yield/command.go
+++ b/cmd/validator/yield/command.go
@@ -1,4 +1,4 @@
-// Copyright © 2022 Weald Technology Trading.
+// Copyright © 2022, 2023 Weald Technology Trading.
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -36,6 +36,7 @@ type command struct {
 
 	// Input.
 	validators string
+	epoch      string
 
 	// Data access.
 	eth2Client eth2client.Service
@@ -63,6 +64,7 @@ func newCommand(_ context.Context) (*command, error) {
 		verbose: viper.GetBool("verbose"),
 		debug:   viper.GetBool("debug"),
 		json:    viper.GetBool("json"),
+		epoch:   viper.GetString("epoch"),
 		results: &output{},
 	}
 
diff --git a/cmd/validator/yield/process.go b/cmd/validator/yield/process.go
index ac57153..c992bbe 100644
--- a/cmd/validator/yield/process.go
+++ b/cmd/validator/yield/process.go
@@ -1,4 +1,4 @@
-// Copyright © 2022 Weald Technology Trading.
+// Copyright © 2022, 2023 Weald Technology Trading.
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -138,17 +138,21 @@ func (c *command) setup(ctx context.Context) error {
 			return errors.New("connection does not provide validator information")
 		}
 
-		validators, err := validatorsProvider.Validators(ctx, "head", nil)
+		epoch, err := util.ParseEpoch(ctx, chainTime, c.epoch)
 		if err != nil {
-			return errors.Wrap(err, "failed to obtain validators")
+			return errors.Wrap(err, "failed to parse epoch")
+		}
+
+		validators, err := validatorsProvider.Validators(ctx, fmt.Sprintf("%d", chainTime.FirstSlotOfEpoch(epoch)), nil)
+		if err != nil {
+			return err
 		}
 
-		currentEpoch := chainTime.CurrentEpoch()
 		activeValidators := decimal.Zero
 		activeValidatorBalance := decimal.Zero
 		for _, validator := range validators {
-			if validator.Validator.ActivationEpoch <= currentEpoch &&
-				validator.Validator.ExitEpoch > currentEpoch {
+			if validator.Validator.ActivationEpoch <= epoch &&
+				validator.Validator.ExitEpoch > epoch {
 				activeValidators = activeValidators.Add(one)
 				activeValidatorBalance = activeValidatorBalance.Add(decimal.NewFromInt(int64(validator.Validator.EffectiveBalance)))
 			}
diff --git a/cmd/validatoryield.go b/cmd/validatoryield.go
index 8f4fc0d..d8e716c 100644
--- a/cmd/validatoryield.go
+++ b/cmd/validatoryield.go
@@ -48,10 +48,14 @@ func init() {
 	validatorCmd.AddCommand(validatorYieldCmd)
 	validatorFlags(validatorYieldCmd)
 	validatorYieldCmd.Flags().String("validators", "", "Number of active validators (default fetches from chain)")
+	validatorYieldCmd.Flags().String("epoch", "", "Epoch at which to calculate yield")
 }
 
 func validatorYieldBindings(cmd *cobra.Command) {
 	if err := viper.BindPFlag("validators", cmd.Flags().Lookup("validators")); err != nil {
 		panic(err)
 	}
+	if err := viper.BindPFlag("epoch", cmd.Flags().Lookup("epoch")); err != nil {
+		panic(err)
+	}
 }
diff --git a/docs/usage.md b/docs/usage.md
index 373a539..5b4259a 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -757,6 +757,7 @@ Withdrawal expected at 2023-04-17T15:08:35 in block 6243041
 `ethdo validator yield` calculates the expected yield given the number of validators.  Options include:
 
 - `validators` use a specified number of validators rather than the current number of active validators
+- `epoch` the epoch for which to calculate yield; defaults to the current epoch
 - `json` obtain detailed information in JSON format
 
 ```sh