feat: Support multiple TF version constraints from module and improve…

… logging (#362)

* feat: Support multiple TF version constaints from module
* Improve logging on reading TF version constraint (moved from #361)
* Align with https://github.com/hashicorp/terraform-config-inspect/blob/master/main.go#L35C2-L37
* Update `test-data/integration-tests/test_versiontf/version.tf` with multiple TF version constraints
* Drop `required_providers` from `test-data/integration-tests/test_versiontf/version.tf` as `tfswitch` does not handle TF providers
* Modified function to return an error in case of non matching constraints
* Added testcase for non matching constraints
* Moved failing testcase to skip-integration tests

---------

Co-authored-by: Johannes Brunswicker <johannes.brunswicker@crownpeak.com>
Co-authored-by: Hugh Wells <hugh@crablab.co.uk>

lib/param_parsing/parameters.go

@@ -60,7 +60,7 @@ func GetParameters() Params {
 	} else if terraformVersionFileExists(params) {
 		params, err = GetParamsFromTerraformVersion(params)
 	} else if isTerraformModule(params) {
-		params, _ = GetVersionFromVersionsTF(params)
+		params, err = GetVersionFromVersionsTF(params)
 	} else if terraGruntFileExists(params) {
 		params, err = GetVersionFromTerragrunt(params)
 	} else {

lib/param_parsing/versiontf.go

@@ -1,18 +1,69 @@
 package param_parsing
 
 import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
 	"github.com/hashicorp/terraform-config-inspect/tfconfig"
 	"github.com/warrensbox/terraform-switcher/lib"
 )
 
 func GetVersionFromVersionsTF(params Params) (Params, error) {
-	logger.Infof("Reading version from terraform module at %q", params.ChDirPath)
-	module, err := tfconfig.LoadModule(params.ChDirPath)
+	var tfConstraints []string
+	var exactConstraints []string
+
+	curDir, err := os.Getwd()
+	if err != nil {
+		logger.Fatalf("Could not get current working directory: %v", err)
+	}
+
+	absPath := params.ChDirPath
+	if !filepath.IsAbs(params.ChDirPath) {
+		absPath, err = filepath.Abs(params.ChDirPath)
+		if err != nil {
+			logger.Fatalf("Could not derive absolute path to %q: %v", params.ChDirPath, err)
+		}
+	}
+
+	relPath, err := filepath.Rel(curDir, absPath)
 	if err != nil {
-		logger.Errorf("Could not load terraform module at %q", params.ChDirPath)
-		return params, err.Err()
+		logger.Fatalf("Could not derive relative path to %q: %v", params.ChDirPath, err)
+	}
+
+	logger.Infof("Reading version from Terraform module at %q", relPath)
+	module, _ := tfconfig.LoadModule(params.ChDirPath)
+	if module.Diagnostics.HasErrors() {
+		logger.Fatalf("Could not load Terraform module at %q", params.ChDirPath)
 	}
-	tfConstraint := module.RequiredCore[0]
+
+	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)
+		}
+
+		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, ", "))
+	}
+
+	tfConstraint := strings.Join(tfConstraints, ", ")
+
 	version, err2 := lib.GetSemver(tfConstraint, params.MirrorURL)
 	if err2 != nil {
 		logger.Errorf("No version found matching %q", tfConstraint)

lib/param_parsing/versiontf_test.go

@@ -4,20 +4,37 @@ import (
 	"fmt"
 	"github.com/hashicorp/go-version"
 	"github.com/warrensbox/terraform-switcher/lib"
+	"strings"
 	"testing"
 )
 
-func TestGetVersionFromVersionsTF(t *testing.T) {
+func TestGetVersionFromVersionsTF_matches_version(t *testing.T) {
 	logger = lib.InitLogger("DEBUG")
 	var params Params
 	params = initParams(params)
 	params.ChDirPath = "../../test-data/integration-tests/test_versiontf"
 	params, _ = GetVersionFromVersionsTF(params)
-	v1, _ := version.NewVersion("1.0.0")
-	v2, _ := version.NewVersion("2.0.0")
+	v1, _ := version.NewVersion("1.0.5")
 	actualVersion, _ := version.NewVersion(params.Version)
-	if !actualVersion.GreaterThanOrEqual(v1) || !actualVersion.LessThan(v2) {
-		t.Error("Determined version is not between 1.0.0 and 2.0.0")
+	if !actualVersion.Equal(v1) {
+		t.Error("Determined version is not 1.0.5")
+	}
+}
+
+func TestGetVersionFromVersionsTF_non_matching_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)
+	if err == nil {
+		t.Error("Expected error but got nil")
+	} 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)
+		}
 	}
 }
 

lib/semver.go

@@ -46,6 +46,7 @@ func SemVerParser(tfconstraint *string, tflist []string) (string, error) {
 			}
 		}
 	}
+
 	return "", fmt.Errorf("did not find version matching constraint: %s", *tfconstraint)
 }
 

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

@@ -1,8 +1,7 @@
 terraform {
   required_version = "~> 1.0.0"
+}
 
-  required_providers {
-    aws        = ">= 2.52.0"
-    kubernetes = ">= 1.11.1"
-  }
-}
+terraform {
+  required_version = "<= 1.0.5"
+}

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

@@ -0,0 +1,11 @@
+terraform {
+  required_version = "~> 1.0.0"
+}
+
+terraform {
+  required_version = "= 1.0.5"
+}
+
+terraform {
+  required_version = "<= 1.0.4"
+}