switch from govaluate to Expr (--filter <expr> option) (#99)

.goreleaser.yml

@@ -26,9 +26,9 @@ builds:
     ignore:
       - goos: wasip1
         goarch: amd64
-      - goos: wasipi
+      - goos: wasip1
         goarch: arm
-      - goos: wasipi
+      - goos: wasip1
         goarch: arm64
       - goos: darwin
         goarch: "386"

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog for rabtap
 
+## v1.40 (2024-08-20)
+
+* govaluate not being maintained since 2017, we switch to
+  [Expr](https://expr-lang.org/) for use as the expression-evaluator of the
+  `--filter <expr>`  option. The syntax of `Expr` is similar, but not the same,
+  so this can be considered a breaking change
+* dependency updates
+
 ## v1.39.3 (2024-06-22)
 
 * simplify code (fanin) and reduce dependencies

README.md

@@ -787,15 +787,18 @@ a *predicate*). Rabtap allows the specification of predicates to be applied
 when printing queues using the `info` command. The output will only proceed
 if the predicate evaluates to `true`.
 
-Rabtap uses the [govalute](https://github.com/Knetic/govaluate) to evaluate the
-predicate. This allows or complex expressions.
+Rabtap uses [Expr](https://expr-lang.org/) to evaluate predicates. This
+allows for complex expressions.
 
-See [official govaluate
-documentation](https://github.com/Knetic/govaluate/blob/master/MANUAL.md) for
-further information.
+See the [official expr-lang
+documentation](https://expr-lang.org/docs/language-definition) for further
+information.
 
-Note: currently the filter is ignored when used in conjunction with
-`--by-connection`.
+> Note: prior to version 1.40, rabtap used
+> [govaluate](https://github.com/Knetic/govaluate) to evaluate expressions.
+> With the switch to [Expr](https://expr-lang.org/), the syntax has changed in
+> some aspects (e.g. `=~` vs `matches`  in regular expression matches). Consult
+> the documentation for details.
 
 #### Evaluation context
 
@@ -813,9 +816,9 @@ broker to be used, e.g.  `http://guest:guest@localhost:15672/api`).
 
 * `rabtap info --filter "exchange.Name == 'amq.direct'" --omit-empty` - print
   only queues bound to exchange `amq.direct` and skip all empty exchanges.
-* `rabtap info --filter "queue.Name =~ '.*test.*'" --omit-empty` - print all
+* `rabtap info --filter "queue.Name matches '.*test.*'" --omit-empty` - print all
   queues with `test` in their name.
-* `rabtap info --filter "queue.Name =~ '.*test.*' && exchange.Type == 'topic'" --omit-empty` - like
+* `rabtap info --filter "queue.Name matches '.*test.*' && exchange.Type == 'topic'" --omit-empty` - like
   before, but consider only exchanges of type `topic`.
 * `rabtap info --filter "queue.Consumers > 0" --omit --stats --consumers` - print 
   all queues with at least one consumer

cmd/rabtap/predicate.go

@@ -5,7 +5,8 @@ package main
 import (
 	"errors"
 
-	"github.com/Knetic/govaluate"
+	"github.com/expr-lang/expr"
+	"github.com/expr-lang/expr/vm"
 )
 
 // Predicate evaluates an expression to a boolean value
@@ -25,23 +26,21 @@ func (s truePredicate) Eval(params map[string]interface{}) (bool, error) {
 // PredicateExpression implements an predicate expression evaluator using
 // the govaluate package
 type PredicateExpression struct {
-	expression *govaluate.EvaluableExpression
+	prog *vm.Program
 }
 
 // NewPredicateExpression creates a new predicate expression
 func NewPredicateExpression(exprstr string) (Predicate, error) {
-	expression, err := govaluate.NewEvaluableExpression(exprstr)
+	prog, err := expr.Compile(exprstr)
 	if err != nil {
 		return nil, err
 	}
-	return &PredicateExpression{
-		expression: expression,
-	}, nil
+	return &PredicateExpression{prog: prog}, nil
 }
 
 // Eval evaluates the expression with a given set of parameters
-func (s PredicateExpression) Eval(params map[string]interface{}) (bool, error) {
-	result, err := s.expression.Evaluate(params)
+func (s PredicateExpression) Eval(env map[string]interface{}) (bool, error) {
+	result, err := expr.Run(s.prog, env)
 	if err != nil {
 		return false, err
 	}

cmd/rabtap/predicate_test.go

@@ -4,58 +4,60 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestTruePredicate(t *testing.T) {
 	res, err := TruePredicate.Eval(nil)
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	assert.True(t, res)
 }
 
 func TestPredicateTrue(t *testing.T) {
 	f, err := NewPredicateExpression("1 == 1")
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	params := map[string]interface{}{}
 	res, err := f.Eval(params)
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	assert.True(t, res)
 }
 
 func TestPredicateFalse(t *testing.T) {
 	f, err := NewPredicateExpression("1 == 0")
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	params := map[string]interface{}{}
 	res, err := f.Eval(params)
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	assert.False(t, res)
 }
 
-func TestPredicateWithParams(t *testing.T) {
-	f, err := NewPredicateExpression("a == 1337 && b.X == 42")
-	assert.Nil(t, err)
+func TestPredicateWithEnv(t *testing.T) {
+	f, err := NewPredicateExpression(`a == 1337 && b.X == 42 && c == "JD"`)
+	require.NoError(t, err)
 	params := make(map[string]interface{}, 1)
 	params["a"] = 1337
 	params["b"] = struct{ X int }{X: 42}
+	params["c"] = "JD"
 	res, err := f.Eval(params)
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	assert.True(t, res)
 }
 
 func TestPredicateReturnsErrorOnInvalidSyntax(t *testing.T) {
-	_, err := NewPredicateExpression("invalid syntax")
-	assert.NotNil(t, err)
+	_, err := NewPredicateExpression(")invalid syntax(")
+	assert.ErrorContains(t, err, "unexpected token")
 }
 
 func TestPredicateReturnsErrorOnEvalError(t *testing.T) {
 	f, err := NewPredicateExpression("(1/a) == 1")
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	_, err = f.Eval(nil)
-	assert.NotNil(t, err)
+	assert.ErrorContains(t, err, "invalid operation")
 }
 func TestPredicateReturnsErrorOnNonBoolReturnValue(t *testing.T) {
 	f, err := NewPredicateExpression("1+1")
-	assert.Nil(t, err)
+	require.NoError(t, err)
 	params := map[string]interface{}{}
 	_, err = f.Eval(params)
-	assert.NotNil(t, err)
+	assert.ErrorContains(t, err, "expression does not evaluate to bool")
 }

go.mod

@@ -3,7 +3,6 @@ module github.com/jandelgado/rabtap
 go 1.18
 
 require (
-	github.com/Knetic/govaluate v0.0.0-20171022003610-9aa49832a739 //v0.0.0-20171022003610-9aa49832a739
 	github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815
 	github.com/fatih/color v1.17.0
 	github.com/google/uuid v1.6.0
@@ -15,7 +14,10 @@ require (
 	golang.org/x/sync v0.8.0
 )
 
-require github.com/stealthrocket/net v0.2.1
+require (
+	github.com/expr-lang/expr v1.16.9
+	github.com/stealthrocket/net v0.2.1
+)
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect

go.sum

@@ -1,10 +1,10 @@
-github.com/Knetic/govaluate v0.0.0-20171022003610-9aa49832a739 h1:g5ROzGMXE/5BOW8kbvOZm+zH6Q+yVUaQBl3vwgLeUqY=
-github.com/Knetic/govaluate v0.0.0-20171022003610-9aa49832a739/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815 h1:bWDMxwH3px2JBh6AyO7hdCn/PkvCZXii8TGj7sbtEbQ=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
+github.com/expr-lang/expr v1.16.9 h1:WUAzmR0JNI9JCiF0/ewwHB1gmcGw5wW7nWt8gc6PpCI=
+github.com/expr-lang/expr v1.16.9/go.mod h1:8/vRC7+7HBzESEqt5kKpYXxrxkr31SaO8r40VO/1IT4=
 github.com/fatih/color v1.17.0 h1:GlRw1BRJxkpqUCBKzKOw098ed57fEsKeNjpTe3cSjK4=
 github.com/fatih/color v1.17.0/go.mod h1:YZ7TlrGPkiz6ku9fK3TLD/pl3CpsiFyu8N92HLgmosI=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=