feat: allow ctx overlay + case sensitive env ctx (#99)

* switch to fork of actionlint

go.mod

@@ -110,3 +110,5 @@ require (
 	google.golang.org/grpc v1.66.3 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 )
+
+replace github.com/rhysd/actionlint => github.com/actions-oss/act-cli-actionlint v0.0.0-20250517100532-8f847f29ba36

go.sum

@@ -15,6 +15,8 @@ github.com/Netflix/go-expect v0.0.0-20220104043353-73e0943537d2 h1:+vx7roKuyA63n
 github.com/Netflix/go-expect v0.0.0-20220104043353-73e0943537d2/go.mod h1:HBCaDeC1lPdgDeDbhX8XFpy1jqjK0IBG8W5K+xYqA0w=
 github.com/ProtonMail/go-crypto v1.1.6 h1:ZcV+Ropw6Qn0AX9brlQLAUXfqLBc7Bl+f/DmNxpLfdw=
 github.com/ProtonMail/go-crypto v1.1.6/go.mod h1:rA3QumHc/FZ8pAHreoekgiAbzpNsfQAosU5td4SnOrE=
+github.com/actions-oss/act-cli-actionlint v0.0.0-20250517100532-8f847f29ba36 h1:QnIPcWM4eVfqRUB3B6sLOwEJrMrTa64qrVqzxF5A21U=
+github.com/actions-oss/act-cli-actionlint v0.0.0-20250517100532-8f847f29ba36/go.mod h1:AE6I6vJEkNaIfWqC2GNE5spIJNhxf8NCtLEKU4NnUXg=
 github.com/adrg/xdg v0.5.3 h1:xRnxJXne7+oWDatRhR1JLnvuccuIeCoBu2rtuLqQB78=
 github.com/adrg/xdg v0.5.3/go.mod h1:nlTsY+NNiCBGCK2tpm09vRqfVzrc2fLmXGpBLF0zlTQ=
 github.com/andreaskoch/go-fswatch v1.0.0 h1:la8nP/HiaFCxP2IM6NZNUCoxgLWuyNFgH0RligBbnJU=
@@ -164,8 +166,6 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 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/rhysd/actionlint v1.7.7 h1:0KgkoNTrYY7vmOCs9BW2AHxLvvpoY9nEUzgBHiPUr0k=
-github.com/rhysd/actionlint v1.7.7/go.mod h1:AE6I6vJEkNaIfWqC2GNE5spIJNhxf8NCtLEKU4NnUXg=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=

pkg/exprparser/interpreter.go

@@ -2,6 +2,7 @@ package exprparser
 
 import (
 	"encoding"
+	"encoding/json"
 	"fmt"
 	"math"
 	"reflect"
@@ -25,8 +26,12 @@ type EvaluationEnvironment struct {
 	Needs     map[string]Needs
 	Inputs    map[string]interface{}
 	HashFiles func([]reflect.Value) (interface{}, error)
+	EnvCS     bool
+	CtxData   map[string]interface{}
 }
 
+type CaseSensitiveDict map[string]string
+
 type Needs struct {
 	Outputs map[string]string `json:"outputs"`
 	Result  string            `json:"result"`
@@ -151,10 +156,17 @@ func (impl *interperterImpl) evaluateNode(exprNode actionlint.ExprNode) (interfa
 }
 
 func (impl *interperterImpl) evaluateVariable(variableNode *actionlint.VariableNode) (interface{}, error) {
-	switch strings.ToLower(variableNode.Name) {
+	lowerName := strings.ToLower(variableNode.Name)
+	if result, err := impl.evaluateOverriddenVariable(lowerName); result != nil || err != nil {
+		return result, err
+	}
+	switch lowerName {
 	case "github":
 		return impl.env.Github, nil
 	case "env":
+		if impl.env.EnvCS {
+			return CaseSensitiveDict(impl.env.Env), nil
+		}
 		return impl.env.Env, nil
 	case "job":
 		return impl.env.Job, nil
@@ -188,6 +200,33 @@ func (impl *interperterImpl) evaluateVariable(variableNode *actionlint.VariableN
 	}
 }
 
+func (impl *interperterImpl) evaluateOverriddenVariable(lowerName string) (interface{}, error) {
+	if cd, ok := impl.env.CtxData[lowerName]; ok {
+		if serverPayload, ok := cd.(map[string]interface{}); ok {
+			if lowerName == "github" {
+				var out map[string]interface{}
+				content, err := json.Marshal(impl.env.Github)
+				if err != nil {
+					return nil, err
+				}
+				err = json.Unmarshal(content, &out)
+				if err != nil {
+					return nil, err
+				}
+				for k, v := range serverPayload {
+					// skip empty values, because github.workspace was set by Gitea Actions to an empty string
+					if _, ok := out[k]; !ok || v != "" && v != nil {
+						out[k] = v
+					}
+				}
+				return out, nil
+			}
+		}
+		return cd, nil
+	}
+	return nil, nil
+}
+
 func (impl *interperterImpl) evaluateIndexAccess(indexAccessNode *actionlint.IndexAccessNode) (interface{}, error) {
 	left, err := impl.evaluateNode(indexAccessNode.Operand)
 	if err != nil {
@@ -280,6 +319,11 @@ func (impl *interperterImpl) getPropertyValue(left reflect.Value, property strin
 		return i, nil
 
 	case reflect.Map:
+		cd, ok := left.Interface().(CaseSensitiveDict)
+		if ok {
+			return cd[property], nil
+		}
+
 		iter := left.MapRange()
 
 		for iter.Next() {

pkg/exprparser/interpreter_test.go

@@ -528,46 +528,58 @@ func TestOperatorsBooleanEvaluation(t *testing.T) {
 
 func TestContexts(t *testing.T) {
 	table := []struct {
-		input    string
+		input            string
-		expected interface{}
+		expected         interface{}
-		name     string
+		name             string
+		caseSensitiveEnv bool
+		ctxdata          map[string]interface{}
 	}{
-		{"github.action", "push", "github-context"},
+		{input: "github.action", expected: "push", name: "github-context"},
-		{"github.event.commits[0].message", nil, "github-context-noexist-prop"},
+		{input: "github.action", expected: "push", name: "github-context", ctxdata: map[string]interface{}{"github": map[string]interface{}{"ref": "refs/heads/test-data"}}},
-		{"fromjson('{\"commits\":[]}').commits[0].message", nil, "github-context-noexist-prop"},
+		{input: "github.ref", expected: "refs/heads/test-data", name: "github-context", ctxdata: map[string]interface{}{"github": map[string]interface{}{"ref": "refs/heads/test-data"}}},
-		{"github.event.pull_request.labels.*.name", nil, "github-context-noexist-prop"},
+		{input: "github.custom-field", expected: "custom-value", name: "github-context", ctxdata: map[string]interface{}{"github": map[string]interface{}{"custom-field": "custom-value"}}},
-		{"env.TEST", "value", "env-context"},
+		{input: "github.event.commits[0].message", expected: nil, name: "github-context-noexist-prop"},
-		{"job.status", "success", "job-context"},
+		{input: "fromjson('{\"commits\":[]}').commits[0].message", expected: nil, name: "github-context-noexist-prop"},
-		{"steps.step-id.outputs.name", "value", "steps-context"},
+		{input: "github.event.pull_request.labels.*.name", expected: nil, name: "github-context-noexist-prop"},
-		{"steps.step-id.conclusion", "success", "steps-context-conclusion"},
+		{input: "env.TEST", expected: "value", name: "env-context"},
-		{"steps.step-id.conclusion && true", true, "steps-context-conclusion"},
+		{input: "env.TEST", expected: "value", name: "env-context", caseSensitiveEnv: true},
-		{"steps.step-id2.conclusion", "skipped", "steps-context-conclusion"},
+		{input: "env.test", expected: "", name: "env-context", caseSensitiveEnv: true},
-		{"steps.step-id2.conclusion && true", true, "steps-context-conclusion"},
+		{input: "env['TEST']", expected: "value", name: "env-context", caseSensitiveEnv: true},
-		{"steps.step-id.outcome", "success", "steps-context-outcome"},
+		{input: "env['test']", expected: "", name: "env-context", caseSensitiveEnv: true},
-		{"steps.step-id['outcome']", "success", "steps-context-outcome"},
+		{input: "env.test", expected: "value", name: "env-context"},
-		{"steps.step-id.outcome == 'success'", true, "steps-context-outcome"},
+		{input: "job.status", expected: "success", name: "job-context"},
-		{"steps.step-id['outcome'] == 'success'", true, "steps-context-outcome"},
+		{input: "steps.step-id.outputs.name", expected: "value", name: "steps-context"},
-		{"steps.step-id.outcome && true", true, "steps-context-outcome"},
+		{input: "steps.step-id.conclusion", expected: "success", name: "steps-context-conclusion"},
-		{"steps['step-id']['outcome'] && true", true, "steps-context-outcome"},
+		{input: "steps.step-id.conclusion && true", expected: true, name: "steps-context-conclusion"},
-		{"steps.step-id2.outcome", "failure", "steps-context-outcome"},
+		{input: "steps.step-id2.conclusion", expected: "skipped", name: "steps-context-conclusion"},
-		{"steps.step-id2.outcome && true", true, "steps-context-outcome"},
+		{input: "steps.step-id2.conclusion && true", expected: true, name: "steps-context-conclusion"},
+		{input: "steps.step-id.outcome", expected: "success", name: "steps-context-outcome"},
+		{input: "steps.step-id['outcome']", expected: "success", name: "steps-context-outcome"},
+		{input: "steps.step-id.outcome == 'success'", expected: true, name: "steps-context-outcome"},
+		{input: "steps.step-id['outcome'] == 'success'", expected: true, name: "steps-context-outcome"},
+		{input: "steps.step-id.outcome && true", expected: true, name: "steps-context-outcome"},
+		{input: "steps['step-id']['outcome'] && true", expected: true, name: "steps-context-outcome"},
+		{input: "steps.step-id2.outcome", expected: "failure", name: "steps-context-outcome"},
+		{input: "steps.step-id2.outcome && true", expected: true, name: "steps-context-outcome"},
 		// Disabled, since the interpreter is still too broken
 		// {"contains(steps.*.outcome, 'success')", true, "steps-context-array-outcome"},
 		// {"contains(steps.*.outcome, 'failure')", true, "steps-context-array-outcome"},
 		// {"contains(steps.*.outputs.name, 'value')", true, "steps-context-array-outputs"},
-		{"runner.os", "Linux", "runner-context"},
+		{input: "runner.os", expected: "Linux", name: "runner-context"},
-		{"secrets.name", "value", "secrets-context"},
+		{input: "secrets.name", expected: "value", name: "secrets-context"},
-		{"vars.name", "value", "vars-context"},
+		{input: "vars.name", expected: "value", name: "vars-context"},
-		{"strategy.fail-fast", true, "strategy-context"},
+		{input: "strategy.fail-fast", expected: true, name: "strategy-context"},
-		{"matrix.os", "Linux", "matrix-context"},
+		{input: "matrix.os", expected: "Linux", name: "matrix-context"},
-		{"needs.job-id.outputs.output-name", "value", "needs-context"},
+		{input: "needs.job-id.outputs.output-name", expected: "value", name: "needs-context"},
-		{"needs.job-id.result", "success", "needs-context"},
+		{input: "needs.job-id.result", expected: "success", name: "needs-context"},
-		{"contains(needs.*.result, 'success')", true, "needs-wildcard-context-contains-success"},
+		{input: "contains(needs.*.result, 'success')", expected: true, name: "needs-wildcard-context-contains-success"},
-		{"contains(needs.*.result, 'failure')", false, "needs-wildcard-context-contains-failure"},
+		{input: "contains(needs.*.result, 'failure')", expected: false, name: "needs-wildcard-context-contains-failure"},
-		{"inputs.name", "value", "inputs-context"},
+		{input: "inputs.name", expected: "value", name: "inputs-context"},
+		{input: "vars.MY_VAR", expected: "refs/heads/test-data", name: "vars-context", ctxdata: map[string]interface{}{"vars": map[string]interface{}{"MY_VAR": "refs/heads/test-data"}}},
+		{input: "vars.MY_VAR", expected: "refs/heads/test-data", name: "vars-context", ctxdata: map[string]interface{}{"vars": map[string]interface{}{"my_var": "refs/heads/test-data"}}},
 	}
 
-	env := &EvaluationEnvironment{
+	env := EvaluationEnvironment{
 		Github: &model.GithubContext{
 			Action: "push",
 		},
@@ -626,7 +638,10 @@ func TestContexts(t *testing.T) {
 
 	for _, tt := range table {
 		t.Run(tt.name, func(t *testing.T) {
-			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, DefaultStatusCheckNone)
+			tenv := env
+			tenv.EnvCS = tt.caseSensitiveEnv
+			tenv.CtxData = tt.ctxdata
+			output, err := NewInterpeter(&tenv, Config{}).Evaluate(tt.input, DefaultStatusCheckNone)
 			assert.Nil(t, err)
 
 			assert.Equal(t, tt.expected, output)

pkg/runner/expression.go

@@ -93,6 +93,7 @@ func (rc *RunContext) NewExpressionEvaluatorWithEnv(ctx context.Context, env map
 	}
 	if rc.JobContainer != nil {
 		ee.Runner = rc.JobContainer.GetRunnerContext(ctx)
+		ee.EnvCS = !rc.JobContainer.IsEnvironmentCaseInsensitive()
 	}
 	return expressionEvaluator{
 		interpreter: exprparser.NewInterpeter(ee, exprparser.Config{