Pass globals to imported jobs

Imported variant command's globals (top-level parameters and options) are now merged into the command, when it misses parameters and options with the same names.

If any imported global's type conflict with the command's corresponding parameter/option type, it fails early so that the imported command doesn't fail due to unexpected value/type provided.

Resolves #29

examples/advanced/nested-import-global-propagation-default/lib/lib.variant

@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}

examples/advanced/nested-import-global-propagation-default/main.variant

@@ -0,0 +1,3 @@
+job "nested" {
+  import = "lib"
+}

examples/advanced/nested-import-global-propagation-incompatible-type/lib/lib.variant

@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}

examples/advanced/nested-import-global-propagation-incompatible-type/main.variant

@@ -0,0 +1,10 @@
+option "project-dir" {
+  # The default works from geodesic shell `projects` folder
+  default = 1
+  description = "Terraform projects directory"
+  type = number
+}
+
+job "nested" {
+  import = "lib"
+}

examples/advanced/nested-import-global-propagation/defaultdir/project

@@ -0,0 +1 @@
+DEFAULT

examples/advanced/nested-import-global-propagation/lib/lib.variant

@@ -0,0 +1,16 @@
+option "project-dir" {
+  description = "Terraform projects directory"
+  default = "./defaultdir"
+  type = string
+}
+
+job "terraform plan" {
+  parameter "project" {
+    type = string
+  }
+
+  exec {
+    command = "bash"
+    args    = ["-c", "echo ${opt.project-dir}/${param.project}"]
+  }
+}

examples/advanced/nested-import-global-propagation/main.variant

@@ -0,0 +1,10 @@
+option "project-dir" {
+  # The default works from geodesic shell `projects` folder
+  default = "./overridedir"
+  description = "Terraform projects directory"
+  type = string
+}
+
+job "nested" {
+  import = "lib"
+}

examples/advanced/nested-import-global-propagation/overridedir/project

@@ -0,0 +1 @@
+OVERRIDE

main.go

@@ -1,5 +1,7 @@
 package variant
 
+import "fmt"
+
 func RunMain(env Env, opts ...Option) error {
 	cmd, path, args := GetPathAndArgsFromEnv(env)
 
@@ -11,7 +13,7 @@ func RunMain(env Env, opts ...Option) error {
 		}
 	}))
 	if err != nil {
-		panic(err)
+		return fmt.Errorf("loading command: %w", err)
 	}
 
 	return m.Run(args, RunOptions{DisableLocking: false})

main_test.go

@@ -154,6 +154,27 @@ func TestExamples(t *testing.T) {
 			args:        []string{"variant", "test"},
 			wd:          "./examples/advanced/import-multi",
 		},
+		{
+			subject:     "nested-import-global-propagation",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation",
+			expectOut:   "./overridedir/project\n",
+		},
+		{
+			subject:     "nested-import-global-propagation-default",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation-default",
+			expectOut:   "./defaultdir/project\n",
+		},
+		{
+			subject:     "nested-import-global-propagation-incompatible-type",
+			args:        []string{"variant", "run", "nested", "terraform", "plan", "project"},
+			variantName: "",
+			wd:          "./examples/advanced/nested-import-global-propagation-incompatible-type",
+			expectErr:   "loading command: merging globals: imported job \"\" has incompatible option \"project-dir\": needs type of cty.Number, encountered cty.String",
+		},
 		{
 			subject:     "options",
 			variantName: "",
@@ -292,8 +313,8 @@ func TestExamples(t *testing.T) {
 			if tc.expectErr != "" {
 				if err == nil {
 					t.Fatalf("Expected error didn't occur")
-				} else if err.Error() != tc.expectErr {
-					t.Fatalf("Unexpected error: want %q, got %q\n%s", tc.expectErr, err.Error(), errOut)
+				} else if d := cmp.Diff(tc.expectErr, err.Error()); d != "" {
+					t.Fatalf("Unexpected error:\nDIFF:\n%s\nSTDERR:\n%s", d, errOut)
 				}
 			} else if err != nil {
 				t.Fatalf("%+v\n%s", err, errOut)

pkg/app/load.go

@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/hashicorp/hcl/v2/ext/typeexpr"
+
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/gohcl"
 	"github.com/hashicorp/hcl/v2/hclparse"
@@ -257,6 +259,8 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 
 	var conf *HCL2Config
 
+	var globals []JobSpec
+
 	jobByName := map[string]JobSpec{}
 	for _, j := range jobs {
 		jobByName[j.Name] = j
@@ -288,7 +292,10 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 						//
 						// If the user-side has a global parameter/option that has the same name as the library-side,
 						// their types MUST match.
-						merged := mergeJobs(importedJob, j)
+						merged, err := mergeParamsAndOpts(importedJob, j)
+						if err != nil {
+							return nil, fmt.Errorf("merging globals: %w", err)
+						}
 
 						merged.Name = ""
 
@@ -302,6 +309,9 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 					} else {
 						// Import the top-level job in the library as the non-top-level job on the user side
 						newJobName = j.Name
+
+						// And merge global parameters and options
+						globals = append(globals, importedJob)
 					}
 
 					importedJob.Name = newJobName
@@ -316,12 +326,27 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 		}
 	}
 
+	root := jobByName[""]
+
+	for _, g := range globals {
+		merged, err := mergeParamsAndOpts(g, root)
+		if err != nil {
+			return nil, fmt.Errorf("merging globals: %w", err)
+		}
+
+		root = *merged
+	}
+
+	jobByName[""] = root
+
 	if conf == nil {
 		conf = cc
 	}
 
 	app.Config = conf
 
+	app.Config.JobSpec = root
+
 	app.JobByName = jobByName
 
 	var newJobs []JobSpec
@@ -335,7 +360,7 @@ func newApp(app *App, cc *HCL2Config, importDir func(string) (*App, error)) (*Ap
 	return app, nil
 }
 
-func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
+func mergeParamsAndOpts(src JobSpec, dst JobSpec) (*JobSpec, error) {
 	paramMap := map[string]Parameter{}
 	optMap := map[string]OptionSpec{}
 
@@ -348,14 +373,38 @@ func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
 	}
 
 	for _, p := range src.Parameters {
-		if _, exists := paramMap[p.Name]; !exists {
+		if existing, exists := paramMap[p.Name]; !exists {
 			paramMap[p.Name] = p
+		} else {
+			exTy, err := typeexpr.TypeConstraint(existing.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing parameter type: %w", err)
+			}
+			toTy, err := typeexpr.TypeConstraint(p.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing parameter type: %w", err)
+			}
+			if exTy != toTy {
+				return nil, fmt.Errorf("imported job %q has incompatible parameter %q: needs type of %v, encountered %v", src.Name, p.Name, exTy.GoString(), toTy.GoString())
+			}
 		}
 	}
 
 	for _, o := range src.Options {
-		if _, exists := optMap[o.Name]; !exists {
+		if existing, exists := optMap[o.Name]; !exists {
 			optMap[o.Name] = o
+		} else {
+			exTy, err := typeexpr.TypeConstraint(existing.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing option type: %w", err)
+			}
+			toTy, err := typeexpr.TypeConstraint(o.Type)
+			if err != nil {
+				return nil, fmt.Errorf("parsing option type: %w", err)
+			}
+			if exTy != toTy {
+				return nil, fmt.Errorf("imported job %q has incompatible option %q: needs type of %v, encountered %v", src.Name, o.Name, exTy.GoString(), toTy.GoString())
+			}
 		}
 	}
 
@@ -375,5 +424,5 @@ func mergeJobs(src JobSpec, dst JobSpec) *JobSpec {
 	dst.Parameters = params
 	dst.Options = opts
 
-	return &dst
+	return &dst, nil
 }