Extract rql package

.golangci.yml

@@ -0,0 +1,42 @@
+run:
+  timeout: 5m
+
+linters-settings:
+  goconst:
+    min-len: 2
+    min-occurrences: 2
+  misspell:
+    locale: US
+  lll:
+    line-length: 140
+  gocritic:
+    enabled-tags:
+      - performance
+      - style
+      - experimental
+    disabled-checks:
+      - paramTypeCombine
+      - unnamedResult
+
+linters:
+  enable:
+    - dupl
+    - exportloopref
+    - gochecknoinits
+    - gocritic
+    - gocyclo
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - misspell
+    - nakedret
+    - prealloc
+    - revive
+    - staticcheck
+    - stylecheck
+    - typecheck
+    - unconvert
+    - unused
+  fast: false
+  disable-all: true

go.mod

@@ -0,0 +1,14 @@
+module go.pkg.cx/rql
+
+go 1.21
+
+require (
+	github.com/alecthomas/participle/v2 v2.1.1
+	github.com/stretchr/testify v1.8.4
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,18 @@
+github.com/alecthomas/assert/v2 v2.3.0 h1:mAsH2wmvjsuvyBvAmCtm7zFsBlb8mIHx5ySLVdDZXL0=
+github.com/alecthomas/assert/v2 v2.3.0/go.mod h1:pXcQ2Asjp247dahGEmsZ6ru0UVwnkhktn7S0bBDLxvQ=
+github.com/alecthomas/participle/v2 v2.1.1 h1:hrjKESvSqGHzRb4yW1ciisFJ4p3MGYih6icjJvbsmV8=
+github.com/alecthomas/participle/v2 v2.1.1/go.mod h1:Y1+hAs8DHPmc3YUFzqllV+eSQ9ljPTk0ZkPMtEdAx2c=
+github.com/alecthomas/repr v0.2.0 h1:HAzS41CIzNW5syS8Mf9UwXhNH1J9aix/BvDRf1Ml2Yk=
+github.com/alecthomas/repr v0.2.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

parser.go

@@ -0,0 +1,42 @@
+package rql
+
+import (
+	"github.com/alecthomas/participle/v2"
+	"github.com/alecthomas/participle/v2/lexer"
+)
+
+var (
+	rqlLexer = lexer.MustSimple([]lexer.SimpleRule{
+		{Name: "whitespace", Pattern: `\s+`},
+		{Name: "String", Pattern: `"[^"]*"`},
+		{Name: "Ident", Pattern: `[a-zA-Z_][a-zA-Z_0-9]*`},
+		{Name: "Punct", Pattern: `[-[!@#$%^&*()+_={};':",.<>?/]|]`},
+	})
+
+	rqlParser = participle.MustBuild[Query](
+		participle.Lexer(rqlLexer),
+		participle.Unquote("String"),
+		participle.UseLookahead(2),
+	)
+)
+
+func Parse(query string) (*Query, error) {
+	return rqlParser.ParseString("", query)
+}
+
+type Operator string
+
+type Values struct {
+	Single *string  `parser:"@String"`
+	List   []string `parser:"| ( '[' @String (',' @String)* ']' )"`
+}
+
+type Predicate struct {
+	Key      string   `parser:"@Ident '.'"`
+	Operator Operator `parser:"@('eq'|'lt'|'lte'|'gt'|'gte'|'like'|'in')"`
+	Values   Values   `parser:"'=' @@"`
+}
+
+type Query struct {
+	Predicates []*Predicate `parser:"@@*"`
+}

parser_test.go

@@ -0,0 +1,87 @@
+package rql
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParse(t *testing.T) {
+	one := "1"
+	john := "John"
+
+	cases := []struct {
+		name       string
+		query      string
+		predicates []*Predicate
+		errMessage string
+	}{
+		{
+			name:       "Valid Query",
+			query:      `id.eq="1"`,
+			predicates: []*Predicate{{Key: "id", Operator: "eq", Values: Values{Single: &one}}},
+			errMessage: "",
+		},
+		{
+			name:       "Multiple Predicates",
+			query:      `id.eq="1" name.eq="John"`,
+			predicates: []*Predicate{{Key: "id", Operator: "eq", Values: Values{Single: &one}}, {Key: "name", Operator: "eq", Values: Values{Single: &john}}},
+			errMessage: "",
+		},
+		{
+			name:  "List Values",
+			query: `id.in=["1", "2", "3"]`,
+			predicates: []*Predicate{
+				{
+					Key:      "id",
+					Operator: "in",
+					Values: Values{
+						List: []string{"1", "2", "3"},
+					},
+				},
+			},
+			errMessage: "",
+		},
+		{
+			name:       "Empty Query",
+			query:      "",
+			predicates: nil,
+			errMessage: "",
+		},
+		{
+			name:       "Whitespace in Query",
+			query:      ` id . eq = "1" `,
+			predicates: []*Predicate{{Key: "id", Operator: "eq", Values: Values{Single: &one}}},
+			errMessage: "",
+		},
+		{
+			name:       "Missing Key",
+			query:      `.eq="1"`,
+			predicates: nil,
+			errMessage: `unexpected token "."`,
+		},
+		{
+			name:       "Invalid Operator",
+			query:      `id.invalid="1"`,
+			predicates: nil,
+			errMessage: `unexpected token "invalid"`,
+		},
+		{
+			name:       "Invalid Query",
+			query:      "invalid_query",
+			predicates: nil,
+			errMessage: `unexpected token "<EOF>"`,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			result, err := Parse(tc.query)
+
+			assert.Equal(t, tc.predicates, result.Predicates)
+			if tc.errMessage != "" {
+				assert.ErrorContains(t, err, tc.errMessage)
+			}
+		})
+	}
+}