Testing Basics

Edge Cases

Edge-case tests cover boundary inputs that ordinary examples might miss.

edge case An edge case is an input near a boundary, such as an empty string or extra spaces.

Edge Cases

rawName
edge_cases.go
Replay: real traced execution (multi-file project)
package main

import (
	"fmt"
	"strings"
)

func normalizeName(name string) string {
	trimmed := strings.TrimSpace(name)
	if trimmed == "" {
		return "Anonymous"
	}
	return trimmed
}

func main() {
	var rawName = "  Ada  "
	normalized := normalizeName(rawName)
	blankInput := strings.TrimSpace(rawName) == ""
	usesFallback := normalized == "Anonymous"

	fmt.Println("raw=", rawName)
	fmt.Println("normalized=", normalized)
	fmt.Println("blankInput=", blankInput)
	fmt.Println("fallback=", usesFallback)
}

package main

import (
	"fmt"
	"strings"
)

func normalizeName(name string) string {
	trimmed := strings.TrimSpace(name)
	if trimmed == "" {
		return "Anonymous"
	}
	return trimmed
}

func main() {
	var rawName = ""
	normalized := normalizeName(rawName)
	blankInput := strings.TrimSpace(rawName) == ""
	usesFallback := normalized == "Anonymous"

	fmt.Println("raw=", rawName)
	fmt.Println("normalized=", normalized)
	fmt.Println("blankInput=", blankInput)
	fmt.Println("fallback=", usesFallback)
}

package main

import (
	"fmt"
	"strings"
)

func normalizeName(name string) string {
	trimmed := strings.TrimSpace(name)
	if trimmed == "" {
		return "Anonymous"
	}
	return trimmed
}

func main() {
	var rawName = "  Go  "
	normalized := normalizeName(rawName)
	blankInput := strings.TrimSpace(rawName) == ""
	usesFallback := normalized == "Anonymous"

	fmt.Println("raw=", rawName)
	fmt.Println("normalized=", normalized)
	fmt.Println("blankInput=", blankInput)
	fmt.Println("fallback=", usesFallback)
}

  1. rawName ← " Ada "

    16func main() {17  var rawName→ "  Ada  " = "  Ada  " //@rawName="", "  Go  "18  normalized := normalizeName(rawName"  Ada  ")19  blankInput := strings.TrimSpace(rawName) == ""

  2. trimmed ← "Ada"

    8func normalizeName(name"  Ada  " string) string {9  trimmed→ "Ada" := strings.TrimSpace(name"  Ada  ")10  if trimmed == "" {11    return "Anonymous"12  }13  return trimmed"Ada"14}

  3. normalized ← "Ada", blankInput ← false, usesFallback ← false

    17  var rawName = "  Ada  " //@rawName="", "  Go  "18  normalized→ "Ada" := normalizeName(rawName"  Ada  ")19  blankInput→ false := strings.TrimSpace(rawName"  Ada  ") == ""20  usesFallback→ false := normalized"Ada" == "Anonymous"2122  fmt.Println("raw=", rawName"  Ada  ")23  fmt.Println("normalized=", normalized"Ada")24  fmt.Println("blankInput=", blankInputfalse)25  fmt.Println("fallback=", usesFallbackfalse)26}
    outputraw=   Ada
normalized= Ada
blankInput= false
fallback= false

  1. rawName ← ""

    16func main() {17  var rawName→ "" = ""18  normalized := normalizeName(rawName"")19  blankInput := strings.TrimSpace(rawName) == ""

  2. trimmed ← ""

    8func normalizeName(name"" string) string {9  trimmed→ "" := strings.TrimSpace(name"")10  if trimmed == "" {

  3. if trimmed == ""

    9trimmed := strings.TrimSpace(name)10if trimmed"" == "" {11  return "Anonymous"12}

  4. normalized ← "Anonymous", blankInput ← true, usesFallback ← true

    17  var rawName = ""18  normalized→ "Anonymous" := normalizeName(rawName"")19  blankInput→ true := strings.TrimSpace(rawName"") == ""20  usesFallback→ true := normalized"Anonymous" == "Anonymous"2122  fmt.Println("raw=", rawName"")23  fmt.Println("normalized=", normalized"Anonymous")24  fmt.Println("blankInput=", blankInputtrue)25  fmt.Println("fallback=", usesFallbacktrue)26}
    outputraw=
normalized= Anonymous
blankInput= true
fallback= true

  1. rawName ← " Go "

    16func main() {17  var rawName→ "  Go  " = "  Go  "18  normalized := normalizeName(rawName"  Go  ")19  blankInput := strings.TrimSpace(rawName) == ""

  2. trimmed ← "Go"

    8func normalizeName(name"  Go  " string) string {9  trimmed→ "Go" := strings.TrimSpace(name"  Go  ")10  if trimmed == "" {11    return "Anonymous"12  }13  return trimmed"Go"14}

  3. normalized ← "Go", blankInput ← false, usesFallback ← false

    17  var rawName = "  Go  "18  normalized→ "Go" := normalizeName(rawName"  Go  ")19  blankInput→ false := strings.TrimSpace(rawName"  Go  ") == ""20  usesFallback→ false := normalized"Go" == "Anonymous"2122  fmt.Println("raw=", rawName"  Go  ")23  fmt.Println("normalized=", normalized"Go")24  fmt.Println("blankInput=", blankInputfalse)25  fmt.Println("fallback=", usesFallbackfalse)26}
    outputraw=   Go
normalized= Go
blankInput= false
fallback= false