refactor: Replace CSV-based YAML function argument parsing

internal/exec/yaml_func_resolution_context_bench_test.go

@@ -117,7 +117,7 @@ func BenchmarkProcessCustomYamlTagsOverhead(b *testing.B) {
 	b.Run("WithoutCycleDetection", func(b *testing.B) {
 		// Simulate old behavior (direct processing without context).
 		for i := 0; i < b.N; i++ {
-			result := processNodes(atmosConfig, input, "test-stack", nil, nil)
+			result, _ := processNodes(atmosConfig, input, "test-stack", nil, nil)
 			_ = result
 		}
 	})

internal/exec/yaml_func_terraform_output.go

@@ -2,9 +2,9 @@ package exec
 
 import (
 	"fmt"
-	"strings"
 
 	errUtils "github.com/cloudposse/atmos/errors"
+	fn "github.com/cloudposse/atmos/pkg/function"
 	log "github.com/cloudposse/atmos/pkg/logger"
 	"github.com/cloudposse/atmos/pkg/perf"
 	"github.com/cloudposse/atmos/pkg/schema"
@@ -19,85 +19,66 @@ func processTagTerraformOutput(
 	input string,
 	currentStack string,
 	stackInfo *schema.ConfigAndStacksInfo,
-) any {
+) (any, error) {
 	return processTagTerraformOutputWithContext(atmosConfig, input, currentStack, nil, stackInfo)
 }
 
-// trackOutputDependency records the dependency in the resolution context and returns a cleanup function.
-func trackOutputDependency(
-	atmosConfig *schema.AtmosConfiguration,
-	resolutionCtx *ResolutionContext,
-	component string,
-	stack string,
-	input string,
-) func() {
-	if resolutionCtx == nil {
-		return func() {}
-	}
-
-	node := DependencyNode{
-		Component:    component,
-		Stack:        stack,
-		FunctionType: "terraform.output",
-		FunctionCall: input,
-	}
-
-	// Check and record this dependency.
-	if err := resolutionCtx.Push(atmosConfig, node); err != nil {
-		errUtils.CheckErrorPrintAndExit(err, "", "")
-	}
-
-	// Return cleanup function.
-	return func() { resolutionCtx.Pop(atmosConfig) }
-}
-
 // processTagTerraformOutputWithContext processes `!terraform.output` YAML tag with cycle detection.
 func processTagTerraformOutputWithContext(
 	atmosConfig *schema.AtmosConfiguration,
 	input string,
 	currentStack string,
 	resolutionCtx *ResolutionContext,
 	stackInfo *schema.ConfigAndStacksInfo,
-) any {
+) (any, error) {
 	defer perf.Track(atmosConfig, "exec.processTagTerraformOutputWithContext")()
 
 	log.Debug("Executing Atmos YAML function", "function", input)
 
 	str, err := getStringAfterTag(input, u.AtmosYamlFuncTerraformOutput)
-	errUtils.CheckErrorPrintAndExit(err, "", "")
-
-	var component string
-	var stack string
-	var output string
-
-	// Split the string into slices based on any whitespace (one or more spaces, tabs, or newlines),
-	// while also ignoring leading and trailing whitespace.
-	// SplitStringByDelimiter splits a string by the delimiter, not splitting inside quotes.
-	parts, err := u.SplitStringByDelimiter(str, ' ')
-	errUtils.CheckErrorPrintAndExit(err, "", "")
-
-	partsLen := len(parts)
-
-	switch partsLen {
-	case 3:
-		component = strings.TrimSpace(parts[0])
-		stack = strings.TrimSpace(parts[1])
-		output = strings.TrimSpace(parts[2])
-	case 2:
-		component = strings.TrimSpace(parts[0])
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse function arguments using the purpose-built parser.
+	// Format: component [stack] expression
+	// Stack is optional - if not provided, uses currentStack.
+	component, stack, output := fn.ParseArgs(str)
+
+	if component == "" {
+		return nil, fmt.Errorf("%w: missing component: %s", errUtils.ErrYamlFuncInvalidArguments, input)
+	}
+
+	if output == "" {
+		return nil, fmt.Errorf("%w: missing output expression: %s", errUtils.ErrYamlFuncInvalidArguments, input)
+	}
+
+	// If no stack was specified, use the current stack.
+	if stack == "" {
 		stack = currentStack
-		output = strings.TrimSpace(parts[1])
 		log.Debug("Executing Atmos YAML function with component and output parameters; using current stack",
 			"function", input,
 			"stack", currentStack,
 		)
-	default:
-		er := fmt.Errorf("%w %s", errUtils.ErrYamlFuncInvalidArguments, input)
-		errUtils.CheckErrorPrintAndExit(er, "", "")
 	}
 
-	// Track dependency and defer cleanup.
-	defer trackOutputDependency(atmosConfig, resolutionCtx, component, stack, input)()
+	// Check for circular dependencies if resolution context is provided.
+	if resolutionCtx != nil {
+		node := DependencyNode{
+			Component:    component,
+			Stack:        stack,
+			FunctionType: "terraform.output",
+			FunctionCall: input,
+		}
+
+		// Check and record this dependency.
+		if err := resolutionCtx.Push(atmosConfig, node); err != nil {
+			return nil, err
+		}
+
+		// Defer pop to ensure we clean up even if there's an error.
+		defer resolutionCtx.Pop(atmosConfig)
+	}
 
 	// Extract authContext and authManager from stackInfo if available.
 	var authContext *schema.AuthContext
@@ -109,17 +90,16 @@ func processTagTerraformOutputWithContext(
 
 	value, exists, err := outputGetter.GetOutput(atmosConfig, stack, component, output, false, authContext, authManager)
 	if err != nil {
-		er := fmt.Errorf("failed to get terraform output for component %s in stack %s, output %s: %w", component, stack, output, err)
-		errUtils.CheckErrorPrintAndExit(er, "", "")
+		return nil, fmt.Errorf("failed to get terraform output for component %s in stack %s, output %s: %w", component, stack, output, err)
 	}
 
 	// If the output doesn't exist, return nil (backward compatible).
 	// This allows YAML functions to reference outputs that don't exist yet.
 	// Use yq fallback syntax (.output // "default") for default values.
 	if !exists {
-		return nil
+		return nil, nil
 	}
 
 	// value may be nil here if the terraform output is legitimately null, which is valid.
-	return value
+	return value, nil
 }

internal/exec/yaml_func_terraform_output_test.go

@@ -61,13 +61,16 @@ func TestYamlFuncTerraformOutput(t *testing.T) {
 	atmosConfig, err := cfg.InitCliConfig(info, true)
 	assert.NoError(t, err)
 
-	d := processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 foo", stack, nil)
+	d, err := processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 foo", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-a", d)
 
-	d = processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 bar", stack, nil)
+	d, err = processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 bar", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-b", d)
 
-	d = processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 nonprod baz", "", nil)
+	d, err = processTagTerraformOutput(&atmosConfig, "!terraform.output component-1 nonprod baz", "", nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-c", d)
 
 	res, err := ExecuteDescribeComponent(&ExecuteDescribeComponentParams{
@@ -102,13 +105,16 @@ func TestYamlFuncTerraformOutput(t *testing.T) {
 		t.Fatalf("Failed to execute 'ExecuteTerraform': %v", err)
 	}
 
-	d = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 foo", stack, nil)
+	d, err = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 foo", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-a", d)
 
-	d = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 nonprod bar", stack, nil)
+	d, err = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 nonprod bar", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-b", d)
 
-	d = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 nonprod baz", "", nil)
+	d, err = processTagTerraformOutput(&atmosConfig, "!terraform.output component-2 nonprod baz", "", nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-c", d)
 
 	res, err = ExecuteDescribeComponent(&ExecuteDescribeComponentParams{

internal/exec/yaml_func_terraform_state.go

@@ -2,9 +2,9 @@ package exec
 
 import (
 	"fmt"
-	"strings"
 
 	errUtils "github.com/cloudposse/atmos/errors"
+	fn "github.com/cloudposse/atmos/pkg/function"
 	log "github.com/cloudposse/atmos/pkg/logger"
 	"github.com/cloudposse/atmos/pkg/perf"
 	"github.com/cloudposse/atmos/pkg/schema"
@@ -19,7 +19,7 @@ func processTagTerraformState(
 	input string,
 	currentStack string,
 	stackInfo *schema.ConfigAndStacksInfo,
-) any {
+) (any, error) {
 	return processTagTerraformStateWithContext(atmosConfig, input, currentStack, nil, stackInfo)
 }
 
@@ -30,42 +30,36 @@ func processTagTerraformStateWithContext(
 	currentStack string,
 	resolutionCtx *ResolutionContext,
 	stackInfo *schema.ConfigAndStacksInfo,
-) any {
+) (any, error) {
 	defer perf.Track(atmosConfig, "exec.processTagTerraformStateWithContext")()
 
 	log.Debug("Executing Atmos YAML function", "function", input)
 
 	str, err := getStringAfterTag(input, u.AtmosYamlFuncTerraformState)
-	errUtils.CheckErrorPrintAndExit(err, "", "")
+	if err != nil {
+		return nil, err
+	}
 
-	var component string
-	var stack string
-	var output string
+	// Parse function arguments using the purpose-built parser.
+	// Format: component [stack] expression
+	// Stack is optional - if not provided, uses currentStack.
+	component, stack, output := fn.ParseArgs(str)
 
-	// Split the string into slices based on any whitespace (one or more spaces, tabs, or newlines),
-	// while also ignoring leading and trailing whitespace.
-	// SplitStringByDelimiter splits a string by the delimiter, not splitting inside quotes.
-	parts, err := u.SplitStringByDelimiter(str, ' ')
-	errUtils.CheckErrorPrintAndExit(err, "", "")
+	if component == "" {
+		return nil, fmt.Errorf("%w: missing component: %s", errUtils.ErrYamlFuncInvalidArguments, input)
+	}
 
-	partsLen := len(parts)
+	if output == "" {
+		return nil, fmt.Errorf("%w: missing output expression: %s", errUtils.ErrYamlFuncInvalidArguments, input)
+	}
 
-	switch partsLen {
-	case 3:
-		component = strings.TrimSpace(parts[0])
-		stack = strings.TrimSpace(parts[1])
-		output = strings.TrimSpace(parts[2])
-	case 2:
-		component = strings.TrimSpace(parts[0])
+	// If no stack was specified, use the current stack.
+	if stack == "" {
 		stack = currentStack
-		output = strings.TrimSpace(parts[1])
 		log.Debug("Executing Atmos YAML function with component and output parameters; using current stack",
 			"function", input,
 			"stack", currentStack,
 		)
-	default:
-		er := fmt.Errorf("%w %s", errUtils.ErrYamlFuncInvalidArguments, input)
-		errUtils.CheckErrorPrintAndExit(er, "", "")
 	}
 
 	// Check for circular dependencies if resolution context is provided.
@@ -79,7 +73,7 @@ func processTagTerraformStateWithContext(
 
 		// Check and record this dependency.
 		if err := resolutionCtx.Push(atmosConfig, node); err != nil {
-			errUtils.CheckErrorPrintAndExit(err, "", "")
+			return nil, err
 		}
 
 		// Defer pop to ensure we clean up even if there's an error.
@@ -95,6 +89,8 @@ func processTagTerraformStateWithContext(
 	}
 
 	value, err := stateGetter.GetState(atmosConfig, input, stack, component, output, false, authContext, authManager)
-	errUtils.CheckErrorPrintAndExit(err, "", "")
-	return value
+	if err != nil {
+		return nil, err
+	}
+	return value, nil
 }

internal/exec/yaml_func_terraform_state_test.go

@@ -61,13 +61,16 @@ func TestYamlFuncTerraformState(t *testing.T) {
 	atmosConfig, err := cfg.InitCliConfig(info, true)
 	assert.NoError(t, err)
 
-	d := processTagTerraformState(&atmosConfig, "!terraform.state component-1 foo", stack, nil)
+	d, err := processTagTerraformState(&atmosConfig, "!terraform.state component-1 foo", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-a", d)
 
-	d = processTagTerraformState(&atmosConfig, "!terraform.state component-1 bar", stack, nil)
+	d, err = processTagTerraformState(&atmosConfig, "!terraform.state component-1 bar", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-b", d)
 
-	d = processTagTerraformState(&atmosConfig, "!terraform.state component-1 nonprod baz", "", nil)
+	d, err = processTagTerraformState(&atmosConfig, "!terraform.state component-1 nonprod baz", "", nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-c", d)
 
 	res, err := ExecuteDescribeComponent(&ExecuteDescribeComponentParams{
@@ -102,13 +105,16 @@ func TestYamlFuncTerraformState(t *testing.T) {
 		t.Fatalf("Failed to execute 'ExecuteTerraform': %v", err)
 	}
 
-	d = processTagTerraformState(&atmosConfig, "!terraform.state component-2 foo", stack, nil)
+	d, err = processTagTerraformState(&atmosConfig, "!terraform.state component-2 foo", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-a", d)
 
-	d = processTagTerraformState(&atmosConfig, "!terraform.state component-2 nonprod bar", stack, nil)
+	d, err = processTagTerraformState(&atmosConfig, "!terraform.state component-2 nonprod bar", stack, nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-b", d)
 
-	d = processTagTerraformState(&atmosConfig, "!terraform.state component-2 nonprod baz", "", nil)
+	d, err = processTagTerraformState(&atmosConfig, "!terraform.state component-2 nonprod baz", "", nil)
+	assert.NoError(t, err)
 	assert.Equal(t, "component-1-c", d)
 
 	res, err = ExecuteDescribeComponent(&ExecuteDescribeComponentParams{