test: add test defending against regression in testnet genesis genera…

…tion (#4741)

gen/generate_test.go

@@ -19,6 +19,7 @@ package gen
 import (
 	"encoding/json"
 	"fmt"
+	"github.com/algorand/go-algorand/data/basics"
 	"io"
 	"os"
 	"path/filepath"
@@ -131,27 +132,37 @@ func TestGenesisJsonCreation(t *testing.T) {
 	t.Parallel()
 
 	type testCase struct {
-		name string
-		gd   GenesisData
+		name             string
+		gd               GenesisData
+		expectedOverride string
 	}
 
-	// `base` is a canonical test confirming `devnet.json` generates the intended `genesis.json`.
-	base := func() testCase {
-		jsonBytes, err := os.ReadFile("devnet.json")
+	defaultGenesisFromFile := func(filename string) GenesisData {
+		jsonBytes, err := os.ReadFile(filename)
 		require.NoError(t, err)
 
 		gd := DefaultGenesis
 		err = json.Unmarshal(jsonBytes, &gd)
 		require.NoError(t, err)
 
-		return testCase{"base", gd}
+		return gd
+	}
+
+	// `base` is a canonical test confirming `devnet.json` generates the intended `genesis.json`.
+	base := func() testCase {
+		return testCase{"base", defaultGenesisFromFile("devnet.json"), ""}
 	}
 
 	// `balance` extends `base` to confirm overriding the rewards pool balance works.
 	balance := func() testCase {
 		gd := base().gd
 		gd.RewardsPoolBalance = 0 // Expect generated balance == MinBalance
-		return testCase{"balance", gd}
+		return testCase{"balance", gd, ""}
+	}
+
+	// `testnet` confirms the generated genesis.json conforms to a previously generated _installer_ artifact.
+	testnet := func() testCase {
+		return testCase{"testnet", defaultGenesisFromFile("testnet.json"), "../installer/genesis/testnet/genesis.json"}
 	}
 
 	// `blotOutRandomValues` replaces random values with static values to support equality checks.
@@ -180,6 +191,24 @@ func TestGenesisJsonCreation(t *testing.T) {
 		}
 	}
 
+	const quickLastPartKeyRound = basics.Round(10) // Ensure quick test execution by reducing rounds.
+
+	// `blotOutFixedValues` replaces values from actual genesis values in order to be compatible with artifacts generated by tests.
+	blotOutFixedValues := func(g *bookkeeping.Genesis) {
+		for i := range g.Allocation {
+			if g.Allocation[i].State.Status == basics.Online {
+				require.Greater(t, g.Allocation[i].State.VoteLastValid, quickLastPartKeyRound)
+				g.Allocation[i].State.VoteLastValid = quickLastPartKeyRound
+			}
+		}
+
+		require.NotZero(t, g.Timestamp)
+		g.Timestamp = 0
+
+		require.NotEmpty(t, g.Network)
+		g.Network = ""
+	}
+
 	saveGeneratedGenesisJSON := func(filename, artifactName string) {
 		src, err := os.Open(filename)
 		require.NoError(t, err)
@@ -206,10 +235,11 @@ func TestGenesisJsonCreation(t *testing.T) {
 	for _, tc := range []testCase{
 		base(),
 		balance(),
+		testnet(),
 	} {
 		t.Run(fmt.Sprintf("name=%v", tc.name), func(t *testing.T) {
 			gd := tc.gd
-			gd.LastPartKeyRound = 10 // Ensure quick test execution by reducing rounds.
+			gd.LastPartKeyRound = uint64(quickLastPartKeyRound)
 
 			outDir := t.TempDir()
 			err := GenerateGenesisFiles(gd, config.Consensus, outDir, nil)
@@ -224,11 +254,22 @@ func TestGenesisJsonCreation(t *testing.T) {
 			roundtrip, err := bookkeeping.LoadGenesisFromFile(generatedFilename)
 			require.NoError(t, err)
 
-			expected, err := bookkeeping.LoadGenesisFromFile("resources/" + artifactName)
+			expectedFilepath := func() string {
+				if len(tc.expectedOverride) == 0 {
+					return "resources/" + artifactName
+				}
+				return tc.expectedOverride
+			}
+			expected, err := bookkeeping.LoadGenesisFromFile(expectedFilepath())
 			saveOnFailure(assert.NoError(t, err))
 
 			blotOutRandomValues(expected.Allocation)
 			blotOutRandomValues(roundtrip.Allocation)
+
+			if len(tc.expectedOverride) > 0 {
+				blotOutFixedValues(&expected)
+			}
+
 			saveOnFailure(assert.Equal(t, expected, roundtrip))
 		})
 	}