refactor(component,generic,http): move test functions to test files and improve code legibility (#1131)

Because

- PR #1121 comments requested moving test-specific functions out of
production code to improve code organization
- Nested if-else structures in test code reduced readability and could
be simplified with early returns

This commit

- Moves `NewTestURLValidator` from `validator.go` to `validator_test.go`
to keep test utilities in test files
- Moves `InitForTest` from `main.go` to `validator_test.go` to separate
test-specific component initialization from production code
- Refactors nested if-else structure in validator test (lines 90-99)
using early returns to improve code legibility
- Removes test functions from production code, reducing binary size and
improving maintainability

Author: pinglin

pkg/component/generic/http/v0/main.go

@@ -83,21 +83,6 @@ func Init(bc base.Component) *component {
 	return comp
 }
 
-// InitForTest creates a component instance for testing with configurable validation
-// whitelist: URLs to allow (nil/empty = allow all external URLs)
-// allowLocalhost: whether to allow localhost/127.x.x.x URLs
-func InitForTest(bc base.Component, whitelist []string, allowLocalhost bool) *component {
-	c := &component{
-		Component:    bc,
-		urlValidator: NewTestURLValidator(whitelist, allowLocalhost),
-	}
-	err := c.LoadDefinition(definitionYAML, setupYAML, tasksYAML, nil, nil)
-	if err != nil {
-		panic(err)
-	}
-	return c
-}
-
 func (c *component) CreateExecution(x base.ComponentExecution) (base.IExecution, error) {
 
 	// We may have different url in batch.

pkg/component/generic/http/v0/validator.go

@@ -28,15 +28,6 @@ func NewURLValidator() URLValidator {
 	return &urlValidator{allowPrivateIPs: false}
 }
 
-// NewTestURLValidator creates a validator for testing
-func NewTestURLValidator(whitelistedEndpoints []string, allowLocalhost bool) URLValidator {
-	return &urlValidator{
-		whitelistedEndpoints: whitelistedEndpoints,
-		allowLocalhost:       allowLocalhost,
-		allowPrivateIPs:      true, // Test mode allows external URLs by default
-	}
-}
-
 // ValidateInput implements the consolidated validation logic
 func (v *urlValidator) ValidateInput(input *httpInput) error {
 	if input == nil {

pkg/component/generic/http/v0/validator_test.go

@@ -8,6 +8,30 @@ import (
 	"github.com/instill-ai/pipeline-backend/pkg/component/base"
 )
 
+// NewTestURLValidator creates a validator for testing
+func NewTestURLValidator(whitelistedEndpoints []string, allowLocalhost bool) URLValidator {
+	return &urlValidator{
+		whitelistedEndpoints: whitelistedEndpoints,
+		allowLocalhost:       allowLocalhost,
+		allowPrivateIPs:      true, // Test mode allows external URLs by default
+	}
+}
+
+// InitForTest creates a component instance for testing with configurable validation
+// whitelist: URLs to allow (nil/empty = allow all external URLs)
+// allowLocalhost: whether to allow localhost/127.x.x.x URLs
+func InitForTest(bc base.Component, whitelist []string, allowLocalhost bool) *component {
+	c := &component{
+		Component:    bc,
+		urlValidator: NewTestURLValidator(whitelist, allowLocalhost),
+	}
+	err := c.LoadDefinition(definitionYAML, setupYAML, tasksYAML, nil, nil)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
 // TestURLValidation tests the URL validation logic comprehensively
 func TestURLValidation(t *testing.T) {
 	c := qt.New(t)
@@ -89,14 +113,17 @@ func TestURLValidation(t *testing.T) {
 				// The actual result depends on config values and DNS resolution
 				if tc.expectBlock {
 					c.Assert(err, qt.IsNotNil, qt.Commentf("Should be blocked: %s (%s)", tc.url, tc.reason))
-				} else {
-					// These might fail due to DNS in test environment, but that's expected
-					// The important thing is that the whitelist logic is in place
-					if err != nil {
-						// If it fails, it should be due to DNS, not whitelist logic
-						c.Assert(err.Error(), qt.Contains, "lookup", qt.Commentf("If blocked, should be due to DNS lookup, not whitelist logic"))
-					}
+					return
 				}
+
+				// These might fail due to DNS in test environment, but that's expected
+				// The important thing is that the whitelist logic is in place
+				if err == nil {
+					return
+				}
+
+				// If it fails, it should be due to DNS, not whitelist logic
+				c.Assert(err.Error(), qt.Contains, "lookup", qt.Commentf("If blocked, should be due to DNS lookup, not whitelist logic"))
 			})
 		}
 	})