Rename Environment field to Context in internal model for consistency

- Update Stack.Environment to Stack.Context in model struct
- Update Result.Environment to Result.Context in diff types
- Update all references in stack resolver to use Context field
- Update all test files to use new Context field names
- Update diff output formatting to display 'Context:' instead of 'Environment:'
- Update JSON output to use 'context' field name instead of 'environment'

This completes the environment-to-context terminology migration by making
the internal data model consistent with the CLI interface. Both CLI flags
and internal data structures now consistently use 'context' terminology.

Author: orien

internal/diff/differ.go

@@ -52,9 +52,9 @@ func NewDiffer(cfClient aws.CloudFormationOperations) *DefaultDiffer {
 // DiffStack compares a resolved stack configuration with the deployed stack
 func (d *DefaultDiffer) DiffStack(ctx context.Context, stack *model.Stack, options Options) (*Result, error) {
 	result := &Result{
-		StackName:   stack.Name,
-		Environment: stack.Environment,
-		Options:     options,
+		StackName: stack.Name,
+		Context:   stack.Context,
+		Options:   options,
 	}
 
 	// Check if stack exists in AWS

internal/diff/differ_test.go

@@ -165,7 +165,7 @@ func createTestDiffer(cfClient *MockCloudFormationClient, templateComp *MockTemp
 func createTestResolvedStack() *model.Stack {
 	return &model.Stack{
 		Name:         "test-stack",
-		Environment:  "dev",
+		Context:      "dev",
 		TemplateBody: `{"AWSTemplateFormatVersion": "2010-09-09"}`,
 		Parameters:   map[string]string{"Param1": "value1", "Param2": "value2"},
 		Tags:         map[string]string{"Environment": "dev", "Project": "test"},
@@ -243,9 +243,10 @@ func TestDefaultDiffer_DiffStack_ExistingStack_NoChanges(t *testing.T) {
 
 	// Verify
 	require.NoError(t, err)
+	// Verify result structure
 	assert.NotNil(t, result)
 	assert.Equal(t, "test-stack", result.StackName)
-	assert.Equal(t, "dev", result.Environment)
+	assert.Equal(t, "dev", result.Context)
 	assert.True(t, result.StackExists)
 	assert.False(t, result.HasChanges())
 	assert.Empty(t, result.ParameterDiffs)
@@ -583,9 +584,9 @@ func TestDefaultDiffer_HandleNewStack(t *testing.T) {
 	// Test data
 	stack := createTestResolvedStack()
 	result := &Result{
-		StackName:   stack.Name,
-		Environment: stack.Environment,
-		Options:     Options{Format: "text"},
+		StackName: stack.Name,
+		Context:   stack.Context,
+		Options:   Options{Format: "text"},
 	}
 
 	// Execute

internal/diff/output.go

@@ -15,7 +15,7 @@ func (r *Result) toText() string {
 	var output strings.Builder
 
 	// Header
-	output.WriteString(fmt.Sprintf("Stack: %s (Environment: %s)\n", r.StackName, r.Environment))
+	output.WriteString(fmt.Sprintf("Stack: %s (Context: %s)\n", r.StackName, r.Context))
 	output.WriteString(strings.Repeat("=", 50) + "\n\n")
 
 	// Handle new stack case
@@ -197,7 +197,7 @@ func (r *Result) toJSON() string {
 	// Create a simplified structure for JSON output
 	jsonResult := map[string]interface{}{
 		"stackName":   r.StackName,
-		"environment": r.Environment,
+		"context": r.Context,
 		"stackExists": r.StackExists,
 		"hasChanges":  r.HasChanges(),
 		"options":     r.Options,

internal/diff/output_test.go

@@ -16,22 +16,22 @@ import (
 func TestResult_String_TextFormat(t *testing.T) {
 	result := &Result{
 		StackName:   "test-stack",
-		Environment: "dev",
+		Context:     "dev",
 		StackExists: true,
 		Options:     Options{Format: "text"},
 	}
 
 	output := result.String()
 
-	assert.Contains(t, output, "Stack: test-stack (Environment: dev)")
+	assert.Contains(t, output, "Stack: test-stack (Context: dev)")
 	assert.Contains(t, output, "Status: NO CHANGES")
 	assert.Contains(t, output, "The deployed stack matches your local configuration.")
 }
 
 func TestResult_String_JSONFormat(t *testing.T) {
 	result := &Result{
 		StackName:   "test-stack",
-		Environment: "dev",
+		Context:     "dev",
 		StackExists: true,
 		Options:     Options{Format: "json"},
 	}
@@ -43,16 +43,15 @@ func TestResult_String_JSONFormat(t *testing.T) {
 	err := json.Unmarshal([]byte(output), &jsonData)
 	require.NoError(t, err)
 
-	assert.Equal(t, "test-stack", jsonData["stackName"])
-	assert.Equal(t, "dev", jsonData["environment"])
+	assert.Equal(t, "dev", jsonData["context"])
 	assert.Equal(t, true, jsonData["stackExists"])
 	assert.Equal(t, false, jsonData["hasChanges"])
 }
 
 func TestResult_ToText_NewStack(t *testing.T) {
 	result := &Result{
 		StackName:   "new-stack",
-		Environment: "prod",
+		Context:     "prod",
 		StackExists: false,
 		ParameterDiffs: []ParameterDiff{
 			{Key: "InstanceType", ProposedValue: "t3.micro", ChangeType: ChangeTypeAdd},
@@ -62,12 +61,11 @@ func TestResult_ToText_NewStack(t *testing.T) {
 			{Key: "Owner", ProposedValue: "team-a", ChangeType: ChangeTypeAdd},
 			{Key: "Project", ProposedValue: "webapp", ChangeType: ChangeTypeAdd},
 		},
-		Options: Options{Format: "text"},
 	}
 
 	output := result.toText()
 
-	assert.Contains(t, output, "Stack: new-stack (Environment: prod)")
+	assert.Contains(t, output, "Stack: new-stack (Context: prod)")
 	assert.Contains(t, output, "Status: NEW STACK")
 	assert.Contains(t, output, "This stack does not exist in AWS and will be created.")
 	assert.Contains(t, output, "Parameters to be set:")
@@ -81,7 +79,7 @@ func TestResult_ToText_NewStack(t *testing.T) {
 func TestResult_ToText_WithChanges(t *testing.T) {
 	result := &Result{
 		StackName:   "existing-stack",
-		Environment: "dev",
+		Context:     "dev",
 		StackExists: true,
 		TemplateChange: &TemplateChange{
 			HasChanges:   true,
@@ -122,7 +120,7 @@ func TestResult_ToText_WithChanges(t *testing.T) {
 	output := result.toText()
 
 	// Header checks
-	assert.Contains(t, output, "Stack: existing-stack (Environment: dev)")
+	assert.Contains(t, output, "Stack: existing-stack (Context: dev)")
 	assert.Contains(t, output, "Status: CHANGES DETECTED")
 
 	// Template changes
@@ -183,7 +181,7 @@ func TestResult_ToText_FilteredOptions(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			result := &Result{
 				StackName:      "test-stack",
-				Environment:    "dev",
+				Context:        "dev",
 				StackExists:    true,
 				TemplateChange: &TemplateChange{HasChanges: true, Diff: "template changes"},
 				ParameterDiffs: []ParameterDiff{{Key: "test", ChangeType: ChangeTypeAdd}},
@@ -206,7 +204,7 @@ func TestResult_ToText_FilteredOptions(t *testing.T) {
 func TestResult_ToJSON_Complete(t *testing.T) {
 	result := &Result{
 		StackName:   "test-stack",
-		Environment: "prod",
+		Context:     "prod",
 		StackExists: true,
 		TemplateChange: &TemplateChange{
 			HasChanges:   true,
@@ -241,7 +239,7 @@ func TestResult_ToJSON_Complete(t *testing.T) {
 
 	// Check top-level fields
 	assert.Equal(t, "test-stack", data["stackName"])
-	assert.Equal(t, "prod", data["environment"])
+	assert.Equal(t, "prod", data["context"])
 	assert.Equal(t, true, data["stackExists"])
 	assert.Equal(t, true, data["hasChanges"])
 
@@ -290,7 +288,7 @@ func TestResult_ToJSON_Complete(t *testing.T) {
 func TestResult_ToJSON_MinimalData(t *testing.T) {
 	result := &Result{
 		StackName:   "minimal-stack",
-		Environment: "test",
+		Context:     "test",
 		StackExists: false,
 		Options:     Options{Format: "json"},
 	}
@@ -302,7 +300,7 @@ func TestResult_ToJSON_MinimalData(t *testing.T) {
 	require.NoError(t, err)
 
 	assert.Equal(t, "minimal-stack", data["stackName"])
-	assert.Equal(t, "test", data["environment"])
+	assert.Equal(t, "test", data["context"])
 	assert.Equal(t, false, data["stackExists"])
 	assert.Equal(t, true, data["hasChanges"]) // New stack (StackExists: false) always has changes
 
@@ -318,7 +316,7 @@ func TestResult_ToJSON_InvalidJSON(t *testing.T) {
 	// We can't easily force json.Marshal to fail in Go, so we test the structure is correct
 	result := &Result{
 		StackName:   "test-stack",
-		Environment: "dev",
+		Context:     "dev",
 		StackExists: true,
 		Options:     Options{Format: "json"},
 	}
@@ -330,7 +328,7 @@ func TestResult_ToJSON_InvalidJSON(t *testing.T) {
 
 	// Should be properly formatted
 	assert.Contains(t, jsonOutput, `"stackName": "test-stack"`)
-	assert.Contains(t, jsonOutput, `"environment": "dev"`)
+	assert.Contains(t, jsonOutput, `"context": "dev"`)
 }
 
 func TestResult_FormatNewStackText(t *testing.T) {

internal/diff/types.go

@@ -33,7 +33,7 @@ type Options struct {
 // Result contains the results of a stack diff operation
 type Result struct {
 	StackName      string
-	Environment    string
+	Context        string
 	StackExists    bool // Whether the stack exists in AWS
 	TemplateChange *TemplateChange
 	ParameterDiffs []ParameterDiff

internal/diff/types_test.go

@@ -54,7 +54,7 @@ func TestResult_DefaultValues(t *testing.T) {
 	result := Result{}
 
 	assert.Equal(t, "", result.StackName)
-	assert.Equal(t, "", result.Environment)
+	assert.Equal(t, "", result.Context)
 	assert.False(t, result.StackExists)
 	assert.Nil(t, result.TemplateChange)
 	assert.Nil(t, result.ParameterDiffs)
@@ -73,7 +73,7 @@ func TestResult_FieldAssignment(t *testing.T) {
 
 	result := Result{
 		StackName:      "test-stack",
-		Environment:    "prod",
+		Context:        "prod",
 		StackExists:    true,
 		TemplateChange: templateChange,
 		ParameterDiffs: paramDiffs,
@@ -83,7 +83,7 @@ func TestResult_FieldAssignment(t *testing.T) {
 	}
 
 	assert.Equal(t, "test-stack", result.StackName)
-	assert.Equal(t, "prod", result.Environment)
+	assert.Equal(t, "prod", result.Context)
 	assert.True(t, result.StackExists)
 	assert.Equal(t, templateChange, result.TemplateChange)
 	assert.Equal(t, paramDiffs, result.ParameterDiffs)
@@ -523,7 +523,7 @@ func TestResult_StringMethod_CallsCorrectFormatter(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			result := Result{
 				StackName:   "test-stack",
-				Environment: "dev",
+				Context:     "dev",
 				StackExists: true,
 				Options:     Options{Format: tt.format},
 			}

internal/model/stack.go

@@ -7,7 +7,7 @@ package model
 // Stack represents a fully resolved stack ready for deployment
 type Stack struct {
 	Name         string
-	Environment  string
+	Context      string
 	TemplateBody string
 	Parameters   map[string]string
 	Tags         map[string]string

internal/model/stack_test.go

@@ -42,7 +42,7 @@ func TestStack_GetTemplateContent(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			rs := &Stack{
 				Name:         "test-stack",
-				Environment:  "dev",
+				Context:      "dev",
 				TemplateBody: tt.templateBody,
 				Parameters:   map[string]string{},
 				Tags:         map[string]string{},
@@ -66,7 +66,7 @@ func TestStack_Creation(t *testing.T) {
 	t.Run("create resolved stack with all fields", func(t *testing.T) {
 		rs := &Stack{
 			Name:         "test-stack",
-			Environment:  "production",
+			Context:      "production",
 			TemplateBody: `{"AWSTemplateFormatVersion": "2010-09-09"}`,
 			Parameters: map[string]string{
 				"Environment":  "prod",
@@ -81,7 +81,7 @@ func TestStack_Creation(t *testing.T) {
 		}
 
 		assert.Equal(t, "test-stack", rs.Name)
-		assert.Equal(t, "production", rs.Environment)
+		assert.Equal(t, "production", rs.Context)
 		assert.Equal(t, `{"AWSTemplateFormatVersion": "2010-09-09"}`, rs.TemplateBody)
 		assert.Equal(t, 2, len(rs.Parameters))
 		assert.Equal(t, "prod", rs.Parameters["Environment"])
@@ -100,7 +100,7 @@ func TestStack_Creation(t *testing.T) {
 	t.Run("create resolved stack with minimal fields", func(t *testing.T) {
 		rs := &Stack{
 			Name:         "minimal-stack",
-			Environment:  "dev",
+			Context:      "dev",
 			TemplateBody: "",
 			Parameters:   map[string]string{},
 			Tags:         map[string]string{},
@@ -109,7 +109,7 @@ func TestStack_Creation(t *testing.T) {
 		}
 
 		assert.Equal(t, "minimal-stack", rs.Name)
-		assert.Equal(t, "dev", rs.Environment)
+		assert.Equal(t, "dev", rs.Context)
 		assert.Equal(t, "", rs.TemplateBody)
 		assert.Empty(t, rs.Parameters)
 		assert.Empty(t, rs.Tags)
@@ -122,13 +122,13 @@ func TestResolvedStacks_Creation(t *testing.T) {
 	t.Run("create resolved stacks with multiple stacks", func(t *testing.T) {
 		stack1 := &Stack{
 			Name:        "vpc-stack",
-			Environment: "dev",
+			Context:     "dev",
 			Parameters:  map[string]string{"VpcCidr": "10.0.0.0/16"},
 		}
 
 		stack2 := &Stack{
 			Name:         "app-stack",
-			Environment:  "dev",
+			Context:      "dev",
 			Parameters:   map[string]string{"Environment": "dev"},
 			Dependencies: []string{"vpc-stack"},
 		}
@@ -165,17 +165,17 @@ func TestStack_NilMaps(t *testing.T) {
 	t.Run("resolved stack with nil maps should work", func(t *testing.T) {
 		rs := &Stack{
 			Name:         "test-stack",
-			Environment:  "dev",
+			Context:      "dev",
 			TemplateBody: "test template",
 			Parameters:   nil,
 			Tags:         nil,
 			Capabilities: nil,
 			Dependencies: nil,
 		}
 
-		// Should not panic when accessing nil maps/slices
+		// These should all work without panicking
 		assert.Equal(t, "test-stack", rs.Name)
-		assert.Equal(t, "dev", rs.Environment)
+		assert.Equal(t, "dev", rs.Context)
 		assert.Equal(t, "test template", rs.TemplateBody)
 		assert.Nil(t, rs.Parameters)
 		assert.Nil(t, rs.Tags)

internal/resolve/stack_resolver.go

@@ -58,7 +58,7 @@ func (r *StackResolver) ResolveStack(ctx context.Context, context string, stackN
 
 	return &model.Stack{
 		Name:         stackConfig.Name,
-		Environment:  context,
+		Context:      context,
 		TemplateBody: templateBody,
 		Parameters:   parameters,
 		Tags:         tags,