Internal Boundaries

The internal directory gives Go projects an import boundary enforced by the toolchain.

internal_boundaries.go

package main

import (
	"fmt"
	"strings"
)

func main() {
	var importPath = 
	ownedPrefix := "example.com/shop/"
	usesInternal := strings.Contains(importPath, "/internal/")
	owned := strings.HasPrefix(importPath, ownedPrefix)
	allowed := !usesInternal || owned

	fmt.Println("import=", importPath)
	fmt.Println("uses_internal=", usesInternal)
	fmt.Println("owned_prefix=", owned)
	fmt.Println("allowed=", allowed)
}

package main

import (
	"fmt"
	"strings"
)

func main() {
	var importPath = 
	ownedPrefix := "example.com/shop/"
	usesInternal := strings.Contains(importPath, "/internal/")
	owned := strings.HasPrefix(importPath, ownedPrefix)
	allowed := !usesInternal || owned

	fmt.Println("import=", importPath)
	fmt.Println("uses_internal=", usesInternal)
	fmt.Println("owned_prefix=", owned)
	fmt.Println("allowed=", allowed)
}

package main

import (
	"fmt"
	"strings"
)

func main() {
	var importPath = 
	ownedPrefix := "example.com/shop/"
	usesInternal := strings.Contains(importPath, "/internal/")
	owned := strings.HasPrefix(importPath, ownedPrefix)
	allowed := !usesInternal || owned

	fmt.Println("import=", importPath)
	fmt.Println("uses_internal=", usesInternal)
	fmt.Println("owned_prefix=", owned)
	fmt.Println("allowed=", allowed)
}

internal packages Model internal imports explicitly so package boundaries stay visible.