prometheus/promql/lex_test.go
Julius Volz 8155cc4992
Expose lexer item types (#5358)
* Expose lexer item types

We have generally agreed to expose AST types / values that are necessary
to make sense of the AST outside of the promql package. Currently the
`UnaryExpr`, `BinaryExpr`, and `AggregateExpr` AST nodes store the lexer
item type to indicate the operator type, but since the individual item
types aren't exposed, an external user of the package cannot determine
the operator type. So this PR exposes them.

Although not all item types are required to make sense of the AST (some
are really only used in the lexer), I decided to expose them all here to
be somewhat more consistent. Another option would be to not use lexer
item types at all in AST nodes.

The concrete motivation is my work on the PromQL->Flux transpiler, but
this ought to be useful for other cases as well.

Signed-off-by: Julius Volz <julius.volz@gmail.com>

* Fix item type names in tests

Signed-off-by: Julius Volz <julius.volz@gmail.com>
2019-03-14 20:53:55 +01:00

712 lines
17 KiB
Go

// Copyright 2015 The Prometheus Authors
// 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
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promql
import (
"fmt"
"reflect"
"testing"
)
type testCase struct {
input string
expected []item
fail bool
seriesDesc bool // Whether to lex a series description.
}
var tests = []struct {
name string
tests []testCase
}{
{
name: "common",
tests: []testCase{
{
input: ",",
expected: []item{{ItemComma, 0, ","}},
}, {
input: "()",
expected: []item{{ItemLeftParen, 0, `(`}, {ItemRightParen, 1, `)`}},
}, {
input: "{}",
expected: []item{{ItemLeftBrace, 0, `{`}, {ItemRightBrace, 1, `}`}},
}, {
input: "[5m]",
expected: []item{
{ItemLeftBracket, 0, `[`},
{ItemDuration, 1, `5m`},
{ItemRightBracket, 3, `]`},
},
}, {
input: "\r\n\r",
expected: []item{},
},
},
},
{
name: "numbers",
tests: []testCase{
{
input: "1",
expected: []item{{ItemNumber, 0, "1"}},
}, {
input: "4.23",
expected: []item{{ItemNumber, 0, "4.23"}},
}, {
input: ".3",
expected: []item{{ItemNumber, 0, ".3"}},
}, {
input: "5.",
expected: []item{{ItemNumber, 0, "5."}},
}, {
input: "NaN",
expected: []item{{ItemNumber, 0, "NaN"}},
}, {
input: "nAN",
expected: []item{{ItemNumber, 0, "nAN"}},
}, {
input: "NaN 123",
expected: []item{{ItemNumber, 0, "NaN"}, {ItemNumber, 4, "123"}},
}, {
input: "NaN123",
expected: []item{{ItemIdentifier, 0, "NaN123"}},
}, {
input: "iNf",
expected: []item{{ItemNumber, 0, "iNf"}},
}, {
input: "Inf",
expected: []item{{ItemNumber, 0, "Inf"}},
}, {
input: "+Inf",
expected: []item{{ItemADD, 0, "+"}, {ItemNumber, 1, "Inf"}},
}, {
input: "+Inf 123",
expected: []item{{ItemADD, 0, "+"}, {ItemNumber, 1, "Inf"}, {ItemNumber, 5, "123"}},
}, {
input: "-Inf",
expected: []item{{ItemSUB, 0, "-"}, {ItemNumber, 1, "Inf"}},
}, {
input: "Infoo",
expected: []item{{ItemIdentifier, 0, "Infoo"}},
}, {
input: "-Infoo",
expected: []item{{ItemSUB, 0, "-"}, {ItemIdentifier, 1, "Infoo"}},
}, {
input: "-Inf 123",
expected: []item{{ItemSUB, 0, "-"}, {ItemNumber, 1, "Inf"}, {ItemNumber, 5, "123"}},
}, {
input: "0x123",
expected: []item{{ItemNumber, 0, "0x123"}},
},
},
},
{
name: "strings",
tests: []testCase{
{
input: "\"test\\tsequence\"",
expected: []item{{ItemString, 0, `"test\tsequence"`}},
},
{
input: "\"test\\\\.expression\"",
expected: []item{{ItemString, 0, `"test\\.expression"`}},
},
{
input: "\"test\\.expression\"",
expected: []item{
{ItemError, 0, "unknown escape sequence U+002E '.'"},
{ItemString, 0, `"test\.expression"`},
},
},
{
input: "`test\\.expression`",
expected: []item{{ItemString, 0, "`test\\.expression`"}},
},
{
// See https://github.com/prometheus/prometheus/issues/939.
input: ".٩",
fail: true,
},
},
},
{
name: "durations",
tests: []testCase{
{
input: "5s",
expected: []item{{ItemDuration, 0, "5s"}},
}, {
input: "123m",
expected: []item{{ItemDuration, 0, "123m"}},
}, {
input: "1h",
expected: []item{{ItemDuration, 0, "1h"}},
}, {
input: "3w",
expected: []item{{ItemDuration, 0, "3w"}},
}, {
input: "1y",
expected: []item{{ItemDuration, 0, "1y"}},
},
},
},
{
name: "identifiers",
tests: []testCase{
{
input: "abc",
expected: []item{{ItemIdentifier, 0, "abc"}},
}, {
input: "a:bc",
expected: []item{{ItemMetricIdentifier, 0, "a:bc"}},
}, {
input: "abc d",
expected: []item{{ItemIdentifier, 0, "abc"}, {ItemIdentifier, 4, "d"}},
}, {
input: ":bc",
expected: []item{{ItemMetricIdentifier, 0, ":bc"}},
}, {
input: "0a:bc",
fail: true,
},
},
},
{
name: "comments",
tests: []testCase{
{
input: "# some comment",
expected: []item{{ItemComment, 0, "# some comment"}},
}, {
input: "5 # 1+1\n5",
expected: []item{
{ItemNumber, 0, "5"},
{ItemComment, 2, "# 1+1"},
{ItemNumber, 8, "5"},
},
},
},
},
{
name: "operators",
tests: []testCase{
{
input: `=`,
expected: []item{{ItemAssign, 0, `=`}},
}, {
// Inside braces equality is a single '=' character.
input: `{=}`,
expected: []item{{ItemLeftBrace, 0, `{`}, {ItemEQL, 1, `=`}, {ItemRightBrace, 2, `}`}},
}, {
input: `==`,
expected: []item{{ItemEQL, 0, `==`}},
}, {
input: `!=`,
expected: []item{{ItemNEQ, 0, `!=`}},
}, {
input: `<`,
expected: []item{{ItemLSS, 0, `<`}},
}, {
input: `>`,
expected: []item{{ItemGTR, 0, `>`}},
}, {
input: `>=`,
expected: []item{{ItemGTE, 0, `>=`}},
}, {
input: `<=`,
expected: []item{{ItemLTE, 0, `<=`}},
}, {
input: `+`,
expected: []item{{ItemADD, 0, `+`}},
}, {
input: `-`,
expected: []item{{ItemSUB, 0, `-`}},
}, {
input: `*`,
expected: []item{{ItemMUL, 0, `*`}},
}, {
input: `/`,
expected: []item{{ItemDIV, 0, `/`}},
}, {
input: `^`,
expected: []item{{ItemPOW, 0, `^`}},
}, {
input: `%`,
expected: []item{{ItemMOD, 0, `%`}},
}, {
input: `AND`,
expected: []item{{ItemLAND, 0, `AND`}},
}, {
input: `or`,
expected: []item{{ItemLOR, 0, `or`}},
}, {
input: `unless`,
expected: []item{{ItemLUnless, 0, `unless`}},
},
},
},
{
name: "aggregators",
tests: []testCase{
{
input: `sum`,
expected: []item{{ItemSum, 0, `sum`}},
}, {
input: `AVG`,
expected: []item{{ItemAvg, 0, `AVG`}},
}, {
input: `MAX`,
expected: []item{{ItemMax, 0, `MAX`}},
}, {
input: `min`,
expected: []item{{ItemMin, 0, `min`}},
}, {
input: `count`,
expected: []item{{ItemCount, 0, `count`}},
}, {
input: `stdvar`,
expected: []item{{ItemStdvar, 0, `stdvar`}},
}, {
input: `stddev`,
expected: []item{{ItemStddev, 0, `stddev`}},
},
},
},
{
name: "keywords",
tests: []testCase{
{
input: "offset",
expected: []item{{ItemOffset, 0, "offset"}},
}, {
input: "by",
expected: []item{{ItemBy, 0, "by"}},
}, {
input: "without",
expected: []item{{ItemWithout, 0, "without"}},
}, {
input: "on",
expected: []item{{ItemOn, 0, "on"}},
}, {
input: "ignoring",
expected: []item{{ItemIgnoring, 0, "ignoring"}},
}, {
input: "group_left",
expected: []item{{ItemGroupLeft, 0, "group_left"}},
}, {
input: "group_right",
expected: []item{{ItemGroupRight, 0, "group_right"}},
}, {
input: "bool",
expected: []item{{ItemBool, 0, "bool"}},
},
},
},
{
name: "selectors",
tests: []testCase{
{
input: `台北`,
fail: true,
}, {
input: `{台北='a'}`,
fail: true,
}, {
input: `{0a='a'}`,
fail: true,
}, {
input: `{foo='bar'}`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `foo`},
{ItemEQL, 4, `=`},
{ItemString, 5, `'bar'`},
{ItemRightBrace, 10, `}`},
},
}, {
input: `{foo="bar"}`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `foo`},
{ItemEQL, 4, `=`},
{ItemString, 5, `"bar"`},
{ItemRightBrace, 10, `}`},
},
}, {
input: `{foo="bar\"bar"}`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `foo`},
{ItemEQL, 4, `=`},
{ItemString, 5, `"bar\"bar"`},
{ItemRightBrace, 15, `}`},
},
}, {
input: `{NaN != "bar" }`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `NaN`},
{ItemNEQ, 5, `!=`},
{ItemString, 8, `"bar"`},
{ItemRightBrace, 14, `}`},
},
}, {
input: `{alert=~"bar" }`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `alert`},
{ItemEQLRegex, 6, `=~`},
{ItemString, 8, `"bar"`},
{ItemRightBrace, 14, `}`},
},
}, {
input: `{on!~"bar"}`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemIdentifier, 1, `on`},
{ItemNEQRegex, 3, `!~`},
{ItemString, 5, `"bar"`},
{ItemRightBrace, 10, `}`},
},
}, {
input: `{alert!#"bar"}`, fail: true,
}, {
input: `{foo:a="bar"}`, fail: true,
},
},
},
{
name: "common errors",
tests: []testCase{
{
input: `=~`, fail: true,
}, {
input: `!~`, fail: true,
}, {
input: `!(`, fail: true,
}, {
input: "1a", fail: true,
},
},
},
{
name: "mismatched parentheses",
tests: []testCase{
{
input: `(`, fail: true,
}, {
input: `())`, fail: true,
}, {
input: `(()`, fail: true,
}, {
input: `{`, fail: true,
}, {
input: `}`, fail: true,
}, {
input: "{{", fail: true,
}, {
input: "{{}}", fail: true,
}, {
input: `[`, fail: true,
}, {
input: `[[`, fail: true,
}, {
input: `[]]`, fail: true,
}, {
input: `[[]]`, fail: true,
}, {
input: `]`, fail: true,
},
},
},
{
name: "encoding issues",
tests: []testCase{
{
input: "\"\xff\"", fail: true,
},
{
input: "`\xff`", fail: true,
},
},
},
{
name: "series descriptions",
tests: []testCase{
{
input: `{} _ 1 x .3`,
expected: []item{
{ItemLeftBrace, 0, `{`},
{ItemRightBrace, 1, `}`},
{ItemSpace, 2, ` `},
{ItemBlank, 3, `_`},
{ItemSpace, 4, ` `},
{ItemNumber, 5, `1`},
{ItemSpace, 6, ` `},
{ItemTimes, 7, `x`},
{ItemSpace, 8, ` `},
{ItemNumber, 9, `.3`},
},
seriesDesc: true,
},
{
input: `metric +Inf Inf NaN`,
expected: []item{
{ItemIdentifier, 0, `metric`},
{ItemSpace, 6, ` `},
{ItemADD, 7, `+`},
{ItemNumber, 8, `Inf`},
{ItemSpace, 11, ` `},
{ItemNumber, 12, `Inf`},
{ItemSpace, 15, ` `},
{ItemNumber, 16, `NaN`},
},
seriesDesc: true,
},
{
input: `metric 1+1x4`,
expected: []item{
{ItemIdentifier, 0, `metric`},
{ItemSpace, 6, ` `},
{ItemNumber, 7, `1`},
{ItemADD, 8, `+`},
{ItemNumber, 9, `1`},
{ItemTimes, 10, `x`},
{ItemNumber, 11, `4`},
},
seriesDesc: true,
},
},
},
{
name: "subqueries",
tests: []testCase{
{
input: `test_name{on!~"bar"}[4m:4s]`,
expected: []item{
{ItemIdentifier, 0, `test_name`},
{ItemLeftBrace, 9, `{`},
{ItemIdentifier, 10, `on`},
{ItemNEQRegex, 12, `!~`},
{ItemString, 14, `"bar"`},
{ItemRightBrace, 19, `}`},
{ItemLeftBracket, 20, `[`},
{ItemDuration, 21, `4m`},
{ItemColon, 23, `:`},
{ItemDuration, 24, `4s`},
{ItemRightBracket, 26, `]`},
},
},
{
input: `test:name{on!~"bar"}[4m:4s]`,
expected: []item{
{ItemMetricIdentifier, 0, `test:name`},
{ItemLeftBrace, 9, `{`},
{ItemIdentifier, 10, `on`},
{ItemNEQRegex, 12, `!~`},
{ItemString, 14, `"bar"`},
{ItemRightBrace, 19, `}`},
{ItemLeftBracket, 20, `[`},
{ItemDuration, 21, `4m`},
{ItemColon, 23, `:`},
{ItemDuration, 24, `4s`},
{ItemRightBracket, 26, `]`},
},
}, {
input: `test:name{on!~"b:ar"}[4m:4s]`,
expected: []item{
{ItemMetricIdentifier, 0, `test:name`},
{ItemLeftBrace, 9, `{`},
{ItemIdentifier, 10, `on`},
{ItemNEQRegex, 12, `!~`},
{ItemString, 14, `"b:ar"`},
{ItemRightBrace, 20, `}`},
{ItemLeftBracket, 21, `[`},
{ItemDuration, 22, `4m`},
{ItemColon, 24, `:`},
{ItemDuration, 25, `4s`},
{ItemRightBracket, 27, `]`},
},
}, {
input: `test:name{on!~"b:ar"}[4m:]`,
expected: []item{
{ItemMetricIdentifier, 0, `test:name`},
{ItemLeftBrace, 9, `{`},
{ItemIdentifier, 10, `on`},
{ItemNEQRegex, 12, `!~`},
{ItemString, 14, `"b:ar"`},
{ItemRightBrace, 20, `}`},
{ItemLeftBracket, 21, `[`},
{ItemDuration, 22, `4m`},
{ItemColon, 24, `:`},
{ItemRightBracket, 25, `]`},
},
}, { // Nested Subquery.
input: `min_over_time(rate(foo{bar="baz"}[2s])[5m:])[4m:3s]`,
expected: []item{
{ItemIdentifier, 0, `min_over_time`},
{ItemLeftParen, 13, `(`},
{ItemIdentifier, 14, `rate`},
{ItemLeftParen, 18, `(`},
{ItemIdentifier, 19, `foo`},
{ItemLeftBrace, 22, `{`},
{ItemIdentifier, 23, `bar`},
{ItemEQL, 26, `=`},
{ItemString, 27, `"baz"`},
{ItemRightBrace, 32, `}`},
{ItemLeftBracket, 33, `[`},
{ItemDuration, 34, `2s`},
{ItemRightBracket, 36, `]`},
{ItemRightParen, 37, `)`},
{ItemLeftBracket, 38, `[`},
{ItemDuration, 39, `5m`},
{ItemColon, 41, `:`},
{ItemRightBracket, 42, `]`},
{ItemRightParen, 43, `)`},
{ItemLeftBracket, 44, `[`},
{ItemDuration, 45, `4m`},
{ItemColon, 47, `:`},
{ItemDuration, 48, `3s`},
{ItemRightBracket, 50, `]`},
},
},
// Subquery with offset.
{
input: `test:name{on!~"b:ar"}[4m:4s] offset 10m`,
expected: []item{
{ItemMetricIdentifier, 0, `test:name`},
{ItemLeftBrace, 9, `{`},
{ItemIdentifier, 10, `on`},
{ItemNEQRegex, 12, `!~`},
{ItemString, 14, `"b:ar"`},
{ItemRightBrace, 20, `}`},
{ItemLeftBracket, 21, `[`},
{ItemDuration, 22, `4m`},
{ItemColon, 24, `:`},
{ItemDuration, 25, `4s`},
{ItemRightBracket, 27, `]`},
{ItemOffset, 29, "offset"},
{ItemDuration, 36, "10m"},
},
}, {
input: `min_over_time(rate(foo{bar="baz"}[2s])[5m:] offset 6m)[4m:3s]`,
expected: []item{
{ItemIdentifier, 0, `min_over_time`},
{ItemLeftParen, 13, `(`},
{ItemIdentifier, 14, `rate`},
{ItemLeftParen, 18, `(`},
{ItemIdentifier, 19, `foo`},
{ItemLeftBrace, 22, `{`},
{ItemIdentifier, 23, `bar`},
{ItemEQL, 26, `=`},
{ItemString, 27, `"baz"`},
{ItemRightBrace, 32, `}`},
{ItemLeftBracket, 33, `[`},
{ItemDuration, 34, `2s`},
{ItemRightBracket, 36, `]`},
{ItemRightParen, 37, `)`},
{ItemLeftBracket, 38, `[`},
{ItemDuration, 39, `5m`},
{ItemColon, 41, `:`},
{ItemRightBracket, 42, `]`},
{ItemOffset, 44, `offset`},
{ItemDuration, 51, `6m`},
{ItemRightParen, 53, `)`},
{ItemLeftBracket, 54, `[`},
{ItemDuration, 55, `4m`},
{ItemColon, 57, `:`},
{ItemDuration, 58, `3s`},
{ItemRightBracket, 60, `]`},
},
},
{
input: `test:name{o:n!~"bar"}[4m:4s]`,
fail: true,
},
{
input: `test:name{on!~"bar"}[4m:4s:4h]`,
fail: true,
},
{
input: `test:name{on!~"bar"}[4m:4s:]`,
fail: true,
},
{
input: `test:name{on!~"bar"}[4m::]`,
fail: true,
},
{
input: `test:name{on!~"bar"}[:4s]`,
fail: true,
},
},
},
}
// TestLexer tests basic functionality of the lexer. More elaborate tests are implemented
// for the parser to avoid duplicated effort.
func TestLexer(t *testing.T) {
for _, typ := range tests {
t.Run(typ.name, func(t *testing.T) {
for i, test := range typ.tests {
l := &lexer{
input: test.input,
items: make(chan item),
seriesDesc: test.seriesDesc,
}
go l.run()
out := []item{}
for it := range l.items {
out = append(out, it)
}
lastItem := out[len(out)-1]
if test.fail {
if lastItem.typ != ItemError {
t.Logf("%d: input %q", i, test.input)
t.Fatalf("expected lexing error but did not fail")
}
continue
}
if lastItem.typ == ItemError {
t.Logf("%d: input %q", i, test.input)
t.Fatalf("unexpected lexing error at position %d: %s", lastItem.pos, lastItem)
}
if !reflect.DeepEqual(lastItem, item{ItemEOF, Pos(len(test.input)), ""}) {
t.Logf("%d: input %q", i, test.input)
t.Fatalf("lexing error: expected output to end with EOF item.\ngot:\n%s", expectedList(out))
}
out = out[:len(out)-1]
if !reflect.DeepEqual(out, test.expected) {
t.Logf("%d: input %q", i, test.input)
t.Fatalf("lexing mismatch:\nexpected:\n%s\ngot:\n%s", expectedList(test.expected), expectedList(out))
}
}
})
}
}
func expectedList(exp []item) string {
s := ""
for _, it := range exp {
s += fmt.Sprintf("\t%#v\n", it)
}
return s
}