Fix for #400 - Whitespaces and Version Constraints (#403)

* added fix for #400 when the comparator is not separated from the version number by a space
* use hashicorp version constraint checker for constraints
* added new testcase

lib/param_parsing/versiontf.go

@@ -1,7 +1,7 @@
 package param_parsing
 
 import (
-	"fmt"
+	semver "github.com/hashicorp/go-version"
 	"os"
 	"path/filepath"
 	"strings"
@@ -12,7 +12,6 @@ import (
 
 func GetVersionFromVersionsTF(params Params) (Params, error) {
 	var tfConstraints []string
-	var exactConstraints []string
 
 	curDir, err := os.Getwd()
 	if err != nil {
@@ -41,25 +40,14 @@ func GetVersionFromVersionsTF(params Params) (Params, error) {
 	requiredVersions := module.RequiredCore
 
 	for key := range requiredVersions {
-		tfConstraint := requiredVersions[key]
-		tfConstraintParts := strings.Fields(tfConstraint)
-
-		if len(tfConstraintParts) > 2 {
-			logger.Fatalf("Invalid version constraint found: %q", tfConstraint)
-		} else if len(tfConstraintParts) == 1 {
-			exactConstraints = append(exactConstraints, tfConstraint)
-			tfConstraint = "= " + tfConstraintParts[0]
-		}
-
-		if tfConstraintParts[0] == "=" {
-			exactConstraints = append(exactConstraints, tfConstraint)
+		// Check if the version contraint is valid
+		constraint, constraintErr := semver.NewConstraint(requiredVersions[key])
+		if constraintErr != nil {
+			logger.Errorf("Invalid version constraint found: %q", requiredVersions[key])
+			return params, constraintErr
 		}
-
-		tfConstraints = append(tfConstraints, tfConstraint)
-	}
-
-	if len(exactConstraints) > 0 && len(tfConstraints) > 1 {
-		return params, fmt.Errorf("exact constraint (%q) cannot be combined with other conditions", strings.Join(exactConstraints, ", "))
+		// It's valid. Add to list
+		tfConstraints = append(tfConstraints, constraint.String())
 	}
 
 	tfConstraint := strings.Join(tfConstraints, ", ")

lib/param_parsing/versiontf_test.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"github.com/hashicorp/go-version"
 	"github.com/warrensbox/terraform-switcher/lib"
-	"strings"
 	"testing"
 )
 
@@ -17,23 +16,24 @@ func TestGetVersionFromVersionsTF_matches_version(t *testing.T) {
 	v1, _ := version.NewVersion("1.0.5")
 	actualVersion, _ := version.NewVersion(params.Version)
 	if !actualVersion.Equal(v1) {
-		t.Error("Determined version is not 1.0.5")
+		t.Errorf("Determined version is not 1.0.5, but %s", params.Version)
 	}
 }
 
-func TestGetVersionFromVersionsTF_non_matching_constraints(t *testing.T) {
+func TestGetVersionFromVersionsTF_impossible_constraints(t *testing.T) {
 	logger = lib.InitLogger("DEBUG")
 	var params Params
 	params = initParams(params)
 	params.ChDirPath = "../../test-data/skip-integration-tests/test_versiontf_non_matching_constraints"
 	params, err := GetVersionFromVersionsTF(params)
+	expectedError := "did not find version matching constraint: ~> 1.0.0, =1.0.5, <= 1.0.4"
 	if err == nil {
-		t.Error("Expected error but got nil")
+		t.Errorf("Expected error '%s', got nil", expectedError)
 	} else {
-		expected := "exact constraint ("
-		expected2 := ") cannot be combined with other conditions"
-		if !strings.Contains(fmt.Sprint(err), expected) || !strings.Contains(fmt.Sprint(err), expected2) {
-			t.Errorf("Expected error string containing %q and %q. Got %q", expected, expected2, err)
+		if err.Error() == expectedError {
+			t.Logf("Got expected error '%s'", err)
+		} else {
+			t.Errorf("Got unexpected error '%s'", err)
 		}
 	}
 }
@@ -47,7 +47,7 @@ func TestGetVersionFromVersionsTF_erroneous_file(t *testing.T) {
 	if err == nil {
 		t.Error("Expected error got nil")
 	} else {
-		expected := "error parsing constraint: Malformed constraint: ~527> 1.0.0"
+		expected := "Malformed constraint: ~527> 1.0.0"
 		if fmt.Sprint(err) != expected {
 			t.Errorf("Expected error %q, got %q", expected, err)
 		}

test-data/integration-tests/test_versiontf/version.tf

@@ -3,5 +3,5 @@ terraform {
 }
 
 terraform {
-  required_version = "<= 1.0.5"
+  required_version = "<=1.0.5"
 }

test-data/skip-integration-tests/test_versiontf_non_matching_constraints/version.tf

@@ -3,7 +3,7 @@ terraform {
 }
 
 terraform {
-  required_version = "= 1.0.5"
+  required_version = "=1.0.5"
 }
 
 terraform {