Add test helpers

Author: wata727

go.mod

@@ -3,6 +3,7 @@ module github.com/terraform-linters/tflint-plugin-sdk
 go 1.13
 
 require (
+	github.com/google/go-cmp v0.3.1
 	github.com/hashicorp/go-hclog v0.10.1
 	github.com/hashicorp/go-plugin v1.0.1
 	github.com/hashicorp/hcl/v2 v2.0.0

go.sum

@@ -17,6 +17,8 @@ github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/hashicorp/go-hclog v0.0.0-20180709165350-ff2cf002a8dd/go.mod h1:9bjs9uLqI8l75knNv3lV1kA55veR+WUPSiKIWcQHudI=
 github.com/hashicorp/go-hclog v0.10.1 h1:uyt/l0dWjJ879yiAu+T7FG3/6QX+zwm4bQ8P7XsYt3o=
 github.com/hashicorp/go-hclog v0.10.1/go.mod h1:whpDNt7SSdeAju8AWKIWsul05p54N/39EeqMAyrmvFQ=

helper/issue.go

@@ -0,0 +1,17 @@
+package helper
+
+import (
+	"github.com/hashicorp/hcl/v2"
+	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
+)
+
+// Issue is a stub that has the same structure as the actually used issue object.
+// This is only used for testing, as the Runner client doesn't depend on the actual Issue structure.
+type Issue struct {
+	Rule    tflint.Rule
+	Message string
+	Range   hcl.Range
+}
+
+// Issues is a list of Issue
+type Issues []*Issue

helper/runner.go

@@ -0,0 +1,87 @@
+package helper
+
+import (
+	"github.com/hashicorp/hcl/v2"
+	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
+	"github.com/zclconf/go-cty/cty/gocty"
+)
+
+// Runner is a pseudo Runner client provided for plugin testing.
+// Actually, it is provided as an RPC client, but for the sake of simplicity,
+// only the methods that satisfy the minimum required Runner interface are implemented.
+// Specifically, there are restrictions on evaluation, annotation comments, module inspection, and so on.
+type Runner struct {
+	Files  map[string]*hcl.File
+	Issues Issues
+}
+
+// WalkResourceAttributes searches for resources and passes the appropriate attributes to the walker function
+func (r *Runner) WalkResourceAttributes(resourceType, attributeName string, walker func(*hcl.Attribute) error) error {
+	for _, file := range r.Files {
+		resources, _, diags := file.Body.PartialContent(&hcl.BodySchema{
+			Blocks: []hcl.BlockHeaderSchema{
+				{
+					Type:       "resource",
+					LabelNames: []string{"type", "name"},
+				},
+			},
+		})
+		if diags.HasErrors() {
+			return diags
+		}
+
+		for _, resource := range resources.Blocks {
+			if resource.Labels[0] != resourceType {
+				continue
+			}
+
+			body, _, diags := resource.Body.PartialContent(&hcl.BodySchema{
+				Attributes: []hcl.AttributeSchema{
+					{
+						Name: attributeName,
+					},
+				},
+			})
+			if diags.HasErrors() {
+				return diags
+			}
+
+			if attribute, ok := body.Attributes[attributeName]; ok {
+				err := walker(attribute)
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+// EvaluateExpr returns a value of the passed expression.
+// Note that there is no evaluation, no type conversion, etc.
+func (r *Runner) EvaluateExpr(expr hcl.Expression, ret interface{}) error {
+	val, diags := expr.Value(&hcl.EvalContext{})
+	if diags.HasErrors() {
+		return diags
+	}
+	return gocty.FromCtyValue(val, ret)
+}
+
+// EmitIssue adds an issue into the self
+func (r *Runner) EmitIssue(rule tflint.Rule, message string, location hcl.Range, meta tflint.Metadata) error {
+	r.Issues = append(r.Issues, &Issue{
+		Rule:    rule,
+		Message: message,
+		Range:   location,
+	})
+	return nil
+}
+
+// EnsureNoError is a method that simply run a function if there is no error
+func (r *Runner) EnsureNoError(err error, proc func() error) error {
+	if err == nil {
+		return proc()
+	}
+	return err
+}

helper/testing.go

@@ -0,0 +1,49 @@
+package helper
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclparse"
+)
+
+// TestRunner returns a pseudo Runner for testing
+func TestRunner(t *testing.T, files map[string]string) *Runner {
+	runner := &Runner{Files: map[string]*hcl.File{}}
+	parser := hclparse.NewParser()
+
+	for name, src := range files {
+		file, diags := parser.ParseHCL([]byte(src), name)
+		if diags.HasErrors() {
+			t.Fatal(diags)
+		}
+		runner.Files[name] = file
+	}
+
+	return runner
+}
+
+// AssertIssues is an assertion helper for comparing issues
+func AssertIssues(t *testing.T, expected Issues, actual Issues) {
+	opts := []cmp.Option{
+		// Byte field will be ignored because it's not important in tests such as positions
+		cmpopts.IgnoreFields(hcl.Pos{}, "Byte"),
+		cmpopts.IgnoreFields(Issue{}, "Rule"),
+	}
+	if !cmp.Equal(expected, actual, opts...) {
+		t.Fatalf("Expected issues are not matched:\n %s\n", cmp.Diff(expected, actual, opts...))
+	}
+}
+
+// AssertIssuesWithoutRange is an assertion helper for comparing issues
+func AssertIssuesWithoutRange(t *testing.T, expected Issues, actual Issues) {
+	opts := []cmp.Option{
+		cmpopts.IgnoreFields(Issue{}, "Range"),
+		cmpopts.IgnoreFields(Issue{}, "Rule"),
+	}
+	if !cmp.Equal(expected, actual, opts...) {
+		t.Fatalf("Expected issues are not matched:\n %s\n", cmp.Diff(expected, actual, opts...))
+	}
+}