go.sum and dependencies
- Go course
- Beginner
- Lesson 11/90
- 4 min
Learn to add dependencies with go get and the go.sum file.
go.sum and dependencies
To add a dependency, run go get github.com/oguz/hello. This downloads the package, adds a require line to go.mod and writes a hash to go.sum.
The go.sum file holds the cryptographic hash of each dependency. This guarantees the downloaded package has not been tampered with.
To clean up dependencies, use go mod tidy; it removes unused ones and adds missing ones.
go mod tidy
Over time, go.mod and go.sum may fill with unused lines. The go mod tidy command cleans these files: it removes unused dependencies and adds missing ones.
The command scans the code, finds which dependencies are actually used, and updates the files accordingly. It is often run in CI pipelines.
To add a new dependency, go get is usually enough; tidy is more about cleanup.
Practice The require line
After go get, the line require github.com/oguz/hello v1.2.0 is added to go.mod. Split this line with strings.Fields and print the package path and version on one line.
Starter code
package main
import (
"fmt"
"strings"
)
func main() {
// buraya yaz
}Sample solution
package main
import (
"fmt"
"strings"
)
func main() {
p := strings.Fields("require github.com/oguz/hello v1.2.0")
fmt.Println(p[1], p[2])
}Expected output
github.com/oguz/hello v1.2.0
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does the go.sum file store?
- The module path
- Source code
- Test results
- Dependency hashes Correct answer
Explanation: go.sum stores dependency hashes.
2 Adding a dependency
To add a dependency:
____ get github.com/x/yTo add a dependency:
go get github.com/x/yExplanation: go get downloads a dependency.
3 Match the module commands
| Term | Meaning |
|---|---|
go get |
Downloads dependency |
go mod tidy |
Cleans up |
go mod init |
Starts module |
go build |
Produces binary |