functional rules engine v0.1

aleybovich · Apr 29, 2024 · 00d67dc · 00d67dc
commit 00d67dc
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diff --git a/.vscode/launch.json b/.vscode/launch.json
@@ -0,0 +1,15 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${fileDirname}"
+        }
+    ]
+}
diff --git a/condition.go b/condition.go
@@ -0,0 +1,116 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/dop251/goja"
+)
+
+type Condition struct {
+	Name        string `yaml:"name"`
+	Description string `yaml:"description"`
+	Check       string `yaml:"check"`
+	True        *struct {
+		Description string `yaml:"description"`
+		Action      string `yaml:"action"`
+		Next        string `yaml:"next"`
+		Terminate   bool   `yaml:"terminate"`
+	} `yaml:"true"`
+	False *struct {
+		Description string `yaml:"description"`
+		Action      string `yaml:"action"`
+		Next        string `yaml:"next"`
+		Terminate   bool   `yaml:"terminate"`
+	} `yaml:"false"`
+}
+
+// Run the conditions recursively
+func (rr *RulesRunner[Context]) runCondition(vm *goja.Runtime, rules *Rules, condition *Condition) error {
+	fmt.Print("Running condition: ", condition.Name, "\n")
+
+	// Evaluate the check function
+	checkFunc, ok := goja.AssertFunction(vm.Get(condition.Name))
+	if !ok {
+		return fmt.Errorf("check function not found: %s", condition.Name)
+	}
+	checkResult, err := checkFunc(goja.Undefined())
+	if err != nil {
+		return fmt.Errorf("error evaluating check function %s: %v", condition.Name, err)
+	}
+
+	if checkResult.ToBoolean() { // If check was true
+		if condition.True != nil {
+			fmt.Print("\tRunning TRUE check: ", condition.True.Description, "\n")
+			if condition.True.Action != "" {
+				// Run the action function
+				actionFuncName := condition.Name + "_true"
+				fmt.Print("\t\tRunning action function: ", actionFuncName, "\n")
+				actionFunc, ok := goja.AssertFunction(vm.Get(actionFuncName))
+				if !ok {
+					return fmt.Errorf("action function not found: %s", actionFuncName)
+				}
+				_, err := actionFunc(goja.Undefined())
+				if err != nil {
+					return fmt.Errorf("error running action function: %v", err)
+				}
+			}
+			if condition.True.Next != "" {
+				nextCondition, err := findConditionByName(rules, condition.True.Next)
+				if err != nil {
+					return fmt.Errorf("unexpected error: condition '%s' not found", condition.True.Next)
+				}
+				err = rr.runCondition(vm, rules, nextCondition)
+				if err != nil {
+					return fmt.Errorf("error while running condition '%s': %v", condition.True.Next, err)
+				}
+			}
+			if condition.True.Terminate {
+				fmt.Print("Terminating\n")
+				return nil
+			}
+		}
+	} else { // if check was false
+		if condition.False != nil {
+			fmt.Print("\tRunning FALSE check: ", condition.False.Description, "\n")
+			if condition.False.Action != "" {
+				// Run the action function
+				actionFuncName := condition.Name + "_false"
+				fmt.Print("\t\tRunning action function: ", actionFuncName, "\n")
+				actionFunc, ok := goja.AssertFunction(vm.Get(actionFuncName))
+				if !ok {
+					return fmt.Errorf("action function not found: %s", actionFuncName)
+				}
+				_, err := actionFunc(goja.Undefined())
+				if err != nil {
+					return fmt.Errorf("error running action function: %v", err)
+				}
+			}
+			if condition.False.Next != "" {
+				nextCondition, err := findConditionByName(rules, condition.False.Next)
+				if err != nil {
+					return fmt.Errorf("unexpected error: condition '%s' not found", condition.False.Next)
+				}
+
+				err = rr.runCondition(vm, rules, nextCondition)
+				if err != nil {
+					return fmt.Errorf("error while running condition '%s': %v", condition.False.Next, err)
+				}
+			}
+			if condition.False.Terminate {
+				fmt.Print("Terminating\n")
+				return nil
+			}
+		}
+	}
+
+	return nil // return from runCondition
+}
+
+func findConditionByName(rule *Rules, name string) (*Condition, error) {
+	for _, condition := range rule.Conditions {
+		if condition.Name == name {
+			return &condition, nil
+		}
+	}
+	return nil, fmt.Errorf("Condition not found: %s", name)
+}
diff --git a/go.mod b/go.mod
@@ -0,0 +1,19 @@
+module yabre
+
+go 1.22.2
+
+require (
+	github.com/dop251/goja v0.0.0-20240220182346-e401ed450204
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dlclark/regexp2 v1.7.0 // indirect
+	github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect
+	github.com/google/pprof v0.0.0-20230207041349-798e818bf904 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.9.0 // indirect
+	golang.org/x/text v0.3.8 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
@@ -0,0 +1,69 @@
+github.com/chzyer/logex v1.2.0/go.mod h1:9+9sk7u7pGNWYMkh0hdiL++6OeibzJccyQU4p4MedaY=
+github.com/chzyer/readline v1.5.0/go.mod h1:x22KAscuvRqlLoK9CsoYsmxoXZMMFVyOl86cAH8qUic=
+github.com/chzyer/test v0.0.0-20210722231415-061457976a23/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+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/dlclark/regexp2 v1.4.1-0.20201116162257-a2a8dda75c91/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
+github.com/dlclark/regexp2 v1.7.0 h1:7lJfhqlPssTb1WQx4yvTHN0uElPEv52sbaECrAQxjAo=
+github.com/dlclark/regexp2 v1.7.0/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dop251/goja v0.0.0-20211022113120-dc8c55024d06/go.mod h1:R9ET47fwRVRPZnOGvHxxhuZcbrMCuiqOz3Rlrh4KSnk=
+github.com/dop251/goja v0.0.0-20240220182346-e401ed450204 h1:O7I1iuzEA7SG+dK8ocOBSlYAA9jBUmCYl/Qa7ey7JAM=
+github.com/dop251/goja v0.0.0-20240220182346-e401ed450204/go.mod h1:QMWlm50DNe14hD7t24KEqZuUdC9sOTy8W6XbCU1mlw4=
+github.com/dop251/goja_nodejs v0.0.0-20210225215109-d91c329300e7/go.mod h1:hn7BA7c8pLvoGndExHudxTDKZ84Pyvv+90pbBjbTz0Y=
+github.com/dop251/goja_nodejs v0.0.0-20211022123610-8dd9abb0616d/go.mod h1:DngW8aVqWbuLRMHItjPUyqdj+HWPvnQe8V8y1nDpIbM=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyLFfuisuzeidWPMPWmECqU=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
+github.com/google/pprof v0.0.0-20230207041349-798e818bf904 h1:4/hN5RUoecvl+RmJRE2YxKWtnnQls6rQjjW5oV7qg2U=
+github.com/google/pprof v0.0.0-20230207041349-798e818bf904/go.mod h1:uglQLonpP8qtYCYyzA+8c/9qtqgA3qsXGYqCPKARAFg=
+github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2/go.mod h1:aYm2/VgdVmcIU8iMfdMvDMsRAQjcfZSKFby6HOFvi/w=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+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/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
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+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
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+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
+golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/rules.go b/rules.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/dop251/goja"
+	"gopkg.in/yaml.v2"
+)
+
+type Rules struct {
+	Conditions map[string]Condition `yaml:"conditions"`
+}
+
+func (rr *RulesRunner[Context]) RunRules(context *Context, startCondition string) (*Context, error) {
+	rules := rr.Rules
+	vm := goja.New()
+
+	// Add context to vm
+	vm.Set("context", *context)
+
+	// Add debug function to vm
+	if rr.DebugCallback != nil {
+		vm.Set("debug", rr.DebugCallback)
+	}
+
+	// Add go functions to vm
+	if rr.GoFunctions != nil {
+		for name, f := range rr.GoFunctions {
+			vm.Set(name, f)
+		}
+	}
+
+	// Add all js functions to the vm
+	err := rr.addJsFunctions(vm)
+	if err != nil {
+		return nil, err
+	}
+
+	// Start running the conditions from the first condition
+	condition, err := findConditionByName(rules, startCondition)
+	if err != nil {
+		return nil, err
+	}
+
+	// Start running the conditions from the first condition
+	err = rr.runCondition(vm, rules, condition)
+
+	// Get the updated context
+	*context = vm.Get("context").ToObject(vm).Export().(Context)
+
+	return context, err
+}
+
+func (rr *RulesRunner[Context]) loadRulesFromYaml(fileName string) (*Rules, error) {
+	yamlFile, err := os.ReadFile(fileName)
+	if err != nil {
+		return nil, fmt.Errorf("error reading YAML file: %v", err)
+	}
+
+	// Parse the YAML into a Rule struct
+	var rules Rules
+	err = yaml.Unmarshal(yamlFile, &rules)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing YAML: %v", err)
+	}
+
+	// add names to conditions from the Rule map
+	for name, condition := range rules.Conditions {
+		condition.Name = name
+		rules.Conditions[name] = condition
+	}
+
+	return &rules, nil
+}
+
+func (rr *RulesRunner[Context]) addJsFunctions(vm *goja.Runtime) error {
+	// add all js functions to the vm
+	for _, condition := range rr.Rules.Conditions {
+		if condition.Check != "" {
+			_, err := vm.RunString(condition.Check)
+			if err != nil {
+				return fmt.Errorf("error injecting check function into vm: %v", err)
+			}
+		}
+		if condition.True != nil && condition.True.Action != "" {
+			_, err := vm.RunString(condition.True.Action)
+			if err != nil {
+				return fmt.Errorf("error injecting action function into vm: %v", err)
+			}
+		}
+		if condition.False != nil && condition.False.Action != "" {
+			_, err := vm.RunString(condition.False.Action)
+			if err != nil {
+				return fmt.Errorf("error injecting action function into vm: %v", err)
+			}
+		}
+	}
+
+	return nil
+}
diff --git a/runner.go b/runner.go
@@ -0,0 +1,44 @@
+package main
+
+type RulesRunner[Context interface{}] struct {
+	Rules         *Rules
+	Context       *Context
+	DebugCallback func(Context, interface{})
+	GoFunctions   map[string]func(...interface{}) (interface{}, error)
+}
+
+type WithOption[Context interface{}] func(*RulesRunner[Context])
+
+// WithDebugCallback sets the DebugCallback option
+func WithDebugCallback[Context interface{}](callback func(Context, interface{})) WithOption[Context] {
+	return func(runner *RulesRunner[Context]) {
+		runner.DebugCallback = callback
+	}
+}
+
+func WithGoFunction[Context interface{}](name string, f func(...interface{}) (interface{}, error)) WithOption[Context] {
+	return func(runner *RulesRunner[Context]) {
+		if runner.GoFunctions == nil {
+			runner.GoFunctions = make(map[string]func(...interface{}) (interface{}, error))
+		}
+		runner.GoFunctions[name] = f
+	}
+}
+
+func NewRulesRunnerFromYaml[Context interface{}](fileName string, context *Context, options ...WithOption[Context]) (*RulesRunner[Context], error) {
+	rr := &RulesRunner[Context]{Context: context}
+
+	// Execute options
+	for _, op := range options {
+		op(rr)
+	}
+
+	// Load the rules from the YAML file
+	rules, err := rr.loadRulesFromYaml(fileName)
+	if err != nil {
+		return nil, err
+	}
+	rr.Rules = rules
+
+	return rr, nil
+}