Fix forgecmd read empty config from forge.toml (#226)

cmd/geth/forgecmd.go

@@ -82,7 +82,10 @@ func readContext(ctx *cli.Context) (*vm.SuaveContext, error) {
 		if err := tomlConfig.NewDecoder(bytes.NewReader(data)).Decode(&config); err != nil {
 			return nil, err
 		}
-		cfg = config.Profile.Suave
+		if config.Profile.Suave != nil {
+			// Only apply the suave config if it exists
+			cfg = config.Profile.Suave
+		}
 	}
 
 	// override the config if the flags are set

cmd/geth/forgecmd_test.go

@@ -27,10 +27,26 @@ func TestForgeReadConfig(t *testing.T) {
 
 	ctx := cli.NewContext(nil, flagSet(t, forgeCommand.Flags), nil)
 
+	// read context from non-existent config file
+	ctx.Set("config", "./testdata/forge_not_exists.toml")
+
+	_, err := readContext(ctx)
+	require.Error(t, err)
+
+	// read context from valid config toml file WITHOUT suave section
+	// it should fallback to the default values
+	ctx.Set("config", "./testdata/forge_noconfig.toml")
+
+	sCtx, err := readContext(ctx)
+	require.NoError(t, err)
+
+	require.Len(t, sCtx.Backend.ExternalWhitelist, 0)
+	require.Len(t, sCtx.Backend.DnsRegistry, 0)
+
 	// read context from config toml file
 	ctx.Set("config", "./testdata/forge.toml")
 
-	sCtx, err := readContext(ctx)
+	sCtx, err = readContext(ctx)
 	require.NoError(t, err)
 	require.Equal(t, sCtx.Backend.ExternalWhitelist, []string{"a", "b"})
 	require.Equal(t, sCtx.Backend.DnsRegistry, map[string]string{"a": "b", "c": "d"})

cmd/geth/testdata/forge_noconfig.toml

@@ -0,0 +1,3 @@
+[profile.ci.fuzz]
+runs = 10_000
+solc_version = "0.8.23"