Merge pull request #2197 from tcolgate/fix_error_types

Report type names in the form used in documentation

promql/engine.go

@@ -120,7 +120,7 @@ func (r *Result) Matrix() (model.Matrix, error) {
 	}
 	v, ok := r.Value.(model.Matrix)
 	if !ok {
-		return nil, fmt.Errorf("query result is not a matrix")
+		return nil, fmt.Errorf("query result is not a range vector")
 	}
 	return v, nil
 }
@@ -286,7 +286,7 @@ func (ng *Engine) NewRangeQuery(qs string, start, end model.Time, interval time.
 		return nil, err
 	}
 	if expr.Type() != model.ValVector && expr.Type() != model.ValScalar {
-		return nil, fmt.Errorf("invalid expression type %q for range query, must be scalar or vector", expr.Type())
+		return nil, fmt.Errorf("invalid expression type %q for range query, must be scalar or instant vector", documentedType(expr.Type()))
 	}
 	qry := ng.newQuery(expr, start, end, interval)
 	qry.q = qs
@@ -581,7 +581,7 @@ func (ev *evaluator) evalScalar(e Expr) *model.Scalar {
 	val := ev.eval(e)
 	sv, ok := val.(*model.Scalar)
 	if !ok {
-		ev.errorf("expected scalar but got %s", val.Type())
+		ev.errorf("expected scalar but got %s", documentedType(val.Type()))
 	}
 	return sv
 }
@@ -591,7 +591,7 @@ func (ev *evaluator) evalVector(e Expr) vector {
 	val := ev.eval(e)
 	vec, ok := val.(vector)
 	if !ok {
-		ev.errorf("expected vector but got %s", val.Type())
+		ev.errorf("expected instant vector but got %s", documentedType(val.Type()))
 	}
 	return vec
 }
@@ -612,11 +612,13 @@ func (ev *evaluator) evalFloat(e Expr) float64 {
 }
 
 // evalMatrix attempts to evaluate e into a matrix and errors otherwise.
+// The error message uses the term "range vector" to match the user facing
+// documentation.
 func (ev *evaluator) evalMatrix(e Expr) matrix {
 	val := ev.eval(e)
 	mat, ok := val.(matrix)
 	if !ok {
-		ev.errorf("expected matrix but got %s", val.Type())
+		ev.errorf("expected range vector but got %s", documentedType(val.Type()))
 	}
 	return mat
 }
@@ -626,7 +628,7 @@ func (ev *evaluator) evalString(e Expr) *model.String {
 	val := ev.eval(e)
 	sv, ok := val.(*model.String)
 	if !ok {
-		ev.errorf("expected string but got %s", val.Type())
+		ev.errorf("expected string but got %s", documentedType(val.Type()))
 	}
 	return sv
 }
@@ -635,7 +637,7 @@ func (ev *evaluator) evalString(e Expr) *model.String {
 func (ev *evaluator) evalOneOf(e Expr, t1, t2 model.ValueType) model.Value {
 	val := ev.eval(e)
 	if val.Type() != t1 && val.Type() != t2 {
-		ev.errorf("expected %s or %s but got %s", t1, t2, val.Type())
+		ev.errorf("expected %s or %s but got %s", documentedType(t1), documentedType(t2), documentedType(val.Type()))
 	}
 	return val
 }
@@ -1337,3 +1339,16 @@ func (g *queryGate) Done() {
 		panic("engine.queryGate.Done: more operations done than started")
 	}
 }
+
+// documentedType returns the internal type to the equivalent
+// user facing terminology as defined in the documentation.
+func documentedType(t model.ValueType) string {
+	switch t.String() {
+	case "vector":
+		return "instant vector"
+	case "matrix":
+		return "range vector"
+	default:
+		return t.String()
+	}
+}

promql/parse.go

@@ -990,7 +990,7 @@ func (p *parser) vectorSelector(name string) *VectorSelector {
 func (p *parser) expectType(node Node, want model.ValueType, context string) {
 	t := p.checkType(node)
 	if t != want {
-		p.errorf("expected type %s in %s, got %s", want, context, t)
+		p.errorf("expected type %s in %s, got %s", documentedType(want), context, documentedType(t))
 	}
 }
 
@@ -1024,20 +1024,20 @@ func (p *parser) checkType(node Node) (typ model.ValueType) {
 	case *EvalStmt:
 		ty := p.checkType(n.Expr)
 		if ty == model.ValNone {
-			p.errorf("evaluation statement must have a valid expression type but got %s", ty)
+			p.errorf("evaluation statement must have a valid expression type but got %s", documentedType(ty))
 		}
 
 	case *RecordStmt:
 		ty := p.checkType(n.Expr)
 		if ty != model.ValVector && ty != model.ValScalar {
-			p.errorf("record statement must have a valid expression of type vector or scalar but got %s", ty)
+			p.errorf("record statement must have a valid expression of type instant vector or scalar but got %s", documentedType(ty))
 		}
 
 	case Expressions:
 		for _, e := range n {
 			ty := p.checkType(e)
 			if ty == model.ValNone {
-				p.errorf("expression must have a valid expression type but got %s", ty)
+				p.errorf("expression must have a valid expression type but got %s", documentedType(ty))
 			}
 		}
 	case *AggregateExpr:
@@ -1060,12 +1060,12 @@ func (p *parser) checkType(node Node) (typ model.ValueType) {
 			p.errorf("binary expression does not support operator %q", n.Op)
 		}
 		if (lt != model.ValScalar && lt != model.ValVector) || (rt != model.ValScalar && rt != model.ValVector) {
-			p.errorf("binary expression must contain only scalar and vector types")
+			p.errorf("binary expression must contain only scalar and instant vector types")
 		}
 
 		if (lt != model.ValVector || rt != model.ValVector) && n.VectorMatching != nil {
 			if len(n.VectorMatching.MatchingLabels) > 0 {
-				p.errorf("vector matching only allowed between vectors")
+				p.errorf("vector matching only allowed between instant vectors")
 			}
 			n.VectorMatching = nil
 		} else {
@@ -1104,7 +1104,7 @@ func (p *parser) checkType(node Node) (typ model.ValueType) {
 			p.errorf("only + and - operators allowed for unary expressions")
 		}
 		if t := p.checkType(n.Expr); t != model.ValScalar && t != model.ValVector {
-			p.errorf("unary expression only allowed on expressions of type scalar or vector, got %q", t)
+			p.errorf("unary expression only allowed on expressions of type scalar or instant vector, got %q", documentedType(t))
 		}
 
 	case *NumberLiteral, *MatrixSelector, *StringLiteral, *VectorSelector:

promql/parse_test.go

@@ -237,11 +237,11 @@ var testExpr = []struct {
 	}, {
 		input:  `-"string"`,
 		fail:   true,
-		errMsg: `unary expression only allowed on expressions of type scalar or vector, got "string"`,
+		errMsg: `unary expression only allowed on expressions of type scalar or instant vector, got "string"`,
 	}, {
 		input:  `-test[5m]`,
 		fail:   true,
-		errMsg: `unary expression only allowed on expressions of type scalar or vector, got "matrix"`,
+		errMsg: `unary expression only allowed on expressions of type scalar or instant vector, got "range vector"`,
 	}, {
 		input:  `*test`,
 		fail:   true,
@@ -772,11 +772,11 @@ var testExpr = []struct {
 	}, {
 		input:  "1 or on(bar) foo",
 		fail:   true,
-		errMsg: "vector matching only allowed between vectors",
+		errMsg: "vector matching only allowed between instant vectors",
 	}, {
 		input:  "foo == on(bar) 10",
 		fail:   true,
-		errMsg: "vector matching only allowed between vectors",
+		errMsg: "vector matching only allowed between instant vectors",
 	}, {
 		input:  "foo and on(bar) group_left(baz) bar",
 		fail:   true,
@@ -1286,7 +1286,7 @@ var testExpr = []struct {
 	}, {
 		input:  `topk(some_metric, other_metric)`,
 		fail:   true,
-		errMsg: "parse error at char 32: expected type scalar in aggregation parameter, got vector",
+		errMsg: "parse error at char 32: expected type scalar in aggregation parameter, got instant vector",
 	}, {
 		input:  `count_values(5, other_metric)`,
 		fail:   true,
@@ -1364,7 +1364,7 @@ var testExpr = []struct {
 	}, {
 		input:  "floor(1)",
 		fail:   true,
-		errMsg: "expected type vector in call to function \"floor\", got scalar",
+		errMsg: "expected type instant vector in call to function \"floor\", got scalar",
 	}, {
 		input:  "non_existent_function_far_bar()",
 		fail:   true,
@@ -1372,7 +1372,7 @@ var testExpr = []struct {
 	}, {
 		input:  "rate(some_metric)",
 		fail:   true,
-		errMsg: "expected type matrix in call to function \"rate\", got vector",
+		errMsg: "expected type range vector in call to function \"rate\", got instant vector",
 	},
 	// Fuzzing regression tests.
 	{