Fix some shadowed variables found by go vet

Signed-off-by: Juanjo Alvarez <juanjo@sourced.tech>

Author: Juanjo Alvarez

auth/common_test.go

@@ -101,21 +101,21 @@ func testAuthentication(
 
 	for _, c := range tests {
 		t.Run(fmt.Sprintf("%s-%s", c.user, c.password), func(t *testing.T) {
-			req := require.New(t)
+			r := require.New(t)
 
-			db, err := dsql.Open("mysql", connString(c.user, c.password))
-			req.NoError(err)
-			_, err = db.Query("SELECT 1")
+			db, e := dsql.Open("mysql", connString(c.user, c.password))
+			r.NoError(e)
+			_, e = db.Query("SELECT 1")
 
 			if c.success {
-				req.NoError(err)
+				r.NoError(e)
 			} else {
-				req.Error(err)
-				req.Contains(err.Error(), "Access denied")
+				r.Error(e)
+				r.Contains(e.Error(), "Access denied")
 			}
 
-			err = db.Close()
-			req.NoError(err)
+			e = db.Close()
+			r.NoError(e)
 
 			if extra != nil {
 				extra(t, c)
@@ -196,20 +196,20 @@ func testAudit(
 
 	for _, c := range tests {
 		t.Run(c.user, func(t *testing.T) {
-			req := require.New(t)
+			r := require.New(t)
 
-			db, err := dsql.Open("mysql", connString(c.user, ""))
-			req.NoError(err)
-			_, err = db.Query(c.query)
+			db, e := dsql.Open("mysql", connString(c.user, ""))
+			r.NoError(e)
+			_, e = db.Query(c.query)
 
 			if c.success {
-				req.NoError(err)
+				r.NoError(e)
 			} else {
-				req.Error(err)
+				r.Error(e)
 			}
 
-			err = db.Close()
-			req.NoError(err)
+			e = db.Close()
+			r.NoError(e)
 
 			if extra != nil {
 				extra(t, c)

mem/table.go

@@ -312,7 +312,7 @@ func (t *Table) HandledFilters(filters []sql.Expression) []sql.Expression {
 	var handled []sql.Expression
 	for _, f := range filters {
 		var hasOtherFields bool
-		f.TransformUp(func(e sql.Expression) (sql.Expression, error) {
+		_, _ = f.TransformUp(func(e sql.Expression) (sql.Expression, error) {
 			if e, ok := e.(*expression.GetField); ok {
 				if e.Table() != t.name || !t.schema.Contains(e.Name(), t.name) {
 					hasOtherFields = true

mem/table_test.go

@@ -194,14 +194,14 @@ func TestTable(t *testing.T) {
 			require.NoError(err)
 
 			for i := 0; i < test.numPartitions; i++ {
-				p, err := pIter.Next()
-				require.NoError(err)
+				p, e := pIter.Next()
+				require.NoError(e)
 
-				iter, err := table.PartitionRows(sql.NewEmptyContext(), p)
-				require.NoError(err)
+				iter, e := table.PartitionRows(sql.NewEmptyContext(), p)
+				require.NoError(e)
 
-				rows, err := sql.RowIterToRows(iter)
-				require.NoError(err)
+				rows, e := sql.RowIterToRows(iter)
+				require.NoError(e)
 
 				expected := table.partitions[string(p.Key())]
 				require.Len(rows, len(expected))

sql/analyzer/optimization_rules.go

@@ -33,7 +33,7 @@ func optimizeDistinct(ctx *sql.Context, a *Analyzer, node sql.Node) (sql.Node, e
 	defer span.Finish()
 
 	a.Log("optimize distinct, node of type: %T", node)
-	if node, ok := node.(*plan.Distinct); ok {
+	if n, ok := node.(*plan.Distinct); ok {
 		var isSorted bool
 		_, _ = node.TransformUp(func(node sql.Node) (sql.Node, error) {
 			a.Log("checking for optimization in node of type: %T", node)
@@ -45,7 +45,7 @@ func optimizeDistinct(ctx *sql.Context, a *Analyzer, node sql.Node) (sql.Node, e
 
 		if isSorted {
 			a.Log("distinct optimized for ordered output")
-			return plan.NewOrderedDistinct(node.Child), nil
+			return plan.NewOrderedDistinct(n.Child), nil
 		}
 	}
 

sql/analyzer/prune_columns.go

@@ -17,12 +17,12 @@ func pruneColumns(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
 	}
 
 	if describe, ok := n.(*plan.DescribeQuery); ok {
-		n, err := pruneColumns(ctx, a, describe.Child)
+		pruned, err := pruneColumns(ctx, a, describe.Child)
 		if err != nil {
 			return nil, err
 		}
 
-		return plan.NewDescribeQuery(describe.Format, n), nil
+		return plan.NewDescribeQuery(describe.Format, pruned), nil
 	}
 
 	columns := make(usedColumns)

sql/analyzer/pushdown.go

@@ -39,13 +39,13 @@ func pushdown(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
 	// First step is to find all col exprs and group them by the table they mention.
 	// Even if they appear multiple times, only the first one will be used.
 	plan.InspectExpressions(n, func(e sql.Expression) bool {
-		if e, ok := e.(*expression.GetField); ok {
-			tf := tableField{e.Table(), e.Name()}
+		if gf, ok := e.(*expression.GetField); ok {
+			tf := tableField{gf.Table(), gf.Name()}
 			if _, ok := tableFields[tf]; !ok {
-				a.Log("found used column %s.%s", e.Table(), e.Name())
+				a.Log("found used column %s.%s", gf.Table(), gf.Name())
 				tableFields[tf] = struct{}{}
-				fieldsByTable[e.Table()] = append(fieldsByTable[e.Table()], e.Name())
-				exprsByTable[e.Table()] = append(exprsByTable[e.Table()], e)
+				fieldsByTable[gf.Table()] = append(fieldsByTable[gf.Table()], gf.Name())
+				exprsByTable[gf.Table()] = append(exprsByTable[gf.Table()], gf)
 			}
 		}
 		return true
@@ -59,14 +59,14 @@ func pushdown(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
 
 	// then find all filters, also by table. Note that filters that mention
 	// more than one table will not be passed to neither.
-	filters := make(filters)
+	filt := make(filters)
 	plan.Inspect(n, func(node sql.Node) bool {
 		a.Log("inspecting node of type: %T", node)
 		switch node := node.(type) {
 		case *plan.Filter:
 			fs := exprToTableFilters(node.Expression)
 			a.Log("found filters for %d tables %s", len(fs), node.Expression)
-			filters.merge(fs)
+			filt.merge(fs)
 		}
 		return true
 	})
@@ -118,7 +118,7 @@ func pushdown(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
 			var table = node.Table
 
 			if ft, ok := table.(sql.FilteredTable); ok {
-				tableFilters := filters[node.Name()]
+				tableFilters := filt[node.Name()]
 				handled := ft.HandledFilters(tableFilters)
 				handledFilters = append(handledFilters, handled...)
 				schema := node.Schema()

sql/catalog.go

@@ -178,8 +178,8 @@ func (c *Catalog) UnlockTables(ctx *Context, id uint32) error {
 			table, err := c.dbs.Table(db, t)
 			if err == nil {
 				if lockable, ok := table.(Lockable); ok {
-					if err := lockable.Unlock(ctx, id); err != nil {
-						errors = append(errors, err.Error())
+					if e := lockable.Unlock(ctx, id); e != nil {
+						errors = append(errors, e.Error())
 					}
 				}
 			} else {

sql/expression/comparison.go

@@ -71,32 +71,32 @@ func (c *comparison) evalLeftAndRight(ctx *sql.Context, row sql.Row) (interface{
 func (c *comparison) castLeftAndRight(left, right interface{}) (interface{}, interface{}, error) {
 	if sql.IsNumber(c.Left().Type()) || sql.IsNumber(c.Right().Type()) {
 		if sql.IsDecimal(c.Left().Type()) || sql.IsDecimal(c.Right().Type()) {
-			left, right, err := convertLeftAndRight(left, right, ConvertToDecimal)
+			l, r, err := convertLeftAndRight(left, right, ConvertToDecimal)
 			if err != nil {
 				return nil, nil, err
 			}
 
 			c.compareType = sql.Float64
-			return left, right, nil
+			return l, r, nil
 		}
 
 		if sql.IsSigned(c.Left().Type()) || sql.IsSigned(c.Right().Type()) {
-			left, right, err := convertLeftAndRight(left, right, ConvertToSigned)
+			l, r, err := convertLeftAndRight(left, right, ConvertToSigned)
 			if err != nil {
 				return nil, nil, err
 			}
 
 			c.compareType = sql.Int64
-			return left, right, nil
+			return l, r, nil
 		}
 
-		left, right, err := convertLeftAndRight(left, right, ConvertToUnsigned)
+		l, r, err := convertLeftAndRight(left, right, ConvertToUnsigned)
 		if err != nil {
 			return nil, nil, err
 		}
 
 		c.compareType = sql.Uint64
-		return left, right, nil
+		return l, r, nil
 	}
 
 	left, right, err := convertLeftAndRight(left, right, ConvertToChar)

sql/expression/function/ceil_round_floor.go

@@ -189,9 +189,9 @@ func (r *Round) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 	dVal := float64(0)
 
 	if r.Right != nil {
-		dTemp, err := r.Right.Eval(ctx, row)
-		if err != nil {
-			return nil, err
+		dTemp, e := r.Right.Eval(ctx, row)
+		if e != nil {
+			return nil, e
 		}
 
 		if dTemp != nil {
@@ -207,8 +207,8 @@ func (r *Round) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 			case int:
 				dVal = float64(dNum)
 			default:
-				dTemp, err = sql.Float64.Convert(dTemp)
-				if err == nil {
+				dTemp, e = sql.Float64.Convert(dTemp)
+				if e == nil {
 					dVal = dTemp.(float64)
 				}
 			}
@@ -280,9 +280,9 @@ func (r *Round) TransformUp(f sql.TransformExprFunc) (sql.Expression, error) {
 
 	args[1] = nil
 	if r.Right != nil {
-		arg, err := r.Right.TransformUp(f)
-		if err != nil {
-			return nil, err
+		arg, e := r.Right.TransformUp(f)
+		if e != nil {
+			return nil, e
 		}
 		args[1] = arg
 	}

sql/expression/function/concat.go

@@ -67,11 +67,11 @@ func (f *Concat) String() string {
 func (f *Concat) TransformUp(fn sql.TransformExprFunc) (sql.Expression, error) {
 	var args = make([]sql.Expression, len(f.args))
 	for i, arg := range f.args {
-		arg, err := arg.TransformUp(fn)
+		a, err := arg.TransformUp(fn)
 		if err != nil {
 			return nil, err
 		}
-		args[i] = arg
+		args[i] = a
 	}
 
 	expr, err := NewConcat(args...)