🔍 Packages

This page covers methods in pkg/composer for single/multi-package operations, defined in packages.go, additional_methods.go, and result_types.go. They correspond to composer's require, remove, show, search, depends, why, why-not, outdated, bump, reinstall, browse, and other subcommands.

🎯 When to Use

➕ Add a new dependency to the project → RequirePackage
➖ Remove an unneeded dependency → Remove
🔎 View an installed package's version/dependencies/source location → ShowPackage or structured ShowPackageInfo
🌐 Find packages on Packagist → Search or structured SearchInfo
🌳 Understand dependency relationships between packages → ShowDependencyTree / WhyPackage / ShowReverseDependencies
⬆️ Find which packages can be upgraded → OutdatedPackages or structured GetOutdatedInfo
🚫 Troubleshoot why a version can't be installed → WhyNotPackage

📋 Method Overview

Method	Signature Summary	Equivalent Command
➕ `RequirePackage`	`RequirePackage(packageName, version string, dev bool) error`	`composer require [--dev] pkg:ver`
`RequirePackageWithOptions`	`RequirePackageWithOptions(packageName, version string, options map[string]string) error`	`composer require [options] pkg:ver`
`RequireMultiple`	`RequireMultiple(packages map[string]string, dev bool) error`	`composer require [--dev] pkg1:ver1 pkg2:ver2 ...`
🧪 `RequireDryRun`	`RequireDryRun(packageName, version string) (string, error)`	`composer require --dry-run pkg:ver`
➖ `Remove`	`Remove(packageName string, dev bool) error`	`composer remove [--dev] pkg`
`RemoveWithOptions`	`RemoveWithOptions(packageName string, options map[string]string) error`	`composer remove [options] pkg`
`RemoveMultiple`	`RemoveMultiple(packages []string, dev bool) error`	`composer remove [--dev] pkg1 pkg2 ...`
🧪 `RemoveDryRun`	`RemoveDryRun(packageName string) (string, error)`	`composer remove --dry-run pkg`
🔎 `ShowPackage`	`ShowPackage(packageName string) (string, error)`	`composer show pkg`
`ShowPackageWithFormat`	`ShowPackageWithFormat(packageName, format string) (string, error)`	`composer show pkg --format=FMT`
✨ `ShowPackageInfo`	`ShowPackageInfo(packageName string) (*PackageInfo, error)`	`composer show pkg --format=json` (structured)
`ShowAllPackages`	`ShowAllPackages() (string, error)`	`composer show`
`ShowDirectPackages`	`ShowDirectPackages() (string, error)`	`composer show --direct`
`ShowSelfPackage`	`ShowSelfPackage() (string, error)`	`composer show --self`
`ShowLatestVersions`	`ShowLatestVersions() (string, error)`	`composer show --latest`
`ShowWithOptions`	`ShowWithOptions(options map[string]string) (string, error)`	`composer show [options]`
🌳 `ShowDependencyTree`	`ShowDependencyTree(packageName string) (string, error)`	`composer show --tree [pkg]`
🔗 `ShowReverseDependencies`	`ShowReverseDependencies(packageName string) (string, error)`	`composer depends pkg`
`DependsWithOptions`	`DependsWithOptions(packageName string, options map[string]string) (string, error)`	`composer depends pkg [options]`
❓ `WhyPackage`	`WhyPackage(packageName string) (string, error)`	`composer why pkg`
`WhyWithOptions`	`WhyWithOptions(packageName string, options map[string]string) (string, error)`	`composer why pkg [options]`
🚫 `WhyNotPackage`	`WhyNotPackage(packageName, version string) (string, error)`	`composer why-not pkg ver`
`WhyNotWithOptions`	`WhyNotWithOptions(packageName, version string, options map[string]string) (string, error)`	`composer why-not pkg ver [options]`
⬆️ `OutdatedPackages`	`OutdatedPackages() (string, error)`	`composer outdated`
`OutdatedPackagesDirect`	`OutdatedPackagesDirect() (string, error)`	`composer outdated --direct`
`OutdatedWithOptions`	`OutdatedWithOptions(options map[string]string) (string, error)`	`composer outdated [options]`
`OutdatedWithFormat`	`OutdatedWithFormat(format string) (string, error)`	`composer outdated --format=FMT`
`ShowOutdatedWithFormat`	`ShowOutdatedWithFormat(format string) (string, error)`	`composer outdated --format=FMT` (alias)
`ShowOutdatedMinorOnly`	`ShowOutdatedMinorOnly() (string, error)`	`composer outdated --minor-only`
✨ `GetOutdatedInfo`	`GetOutdatedInfo() (*OutdatedResult, error)`	`composer outdated --format=json` (structured)
✨ `GetOutdatedInfoWithOptions`	`GetOutdatedInfoWithOptions(options map[string]string) (*OutdatedResult, error)`	Same + options
🌐 `Search`	`Search(query string) (string, error)`	`composer search query`
`SearchWithFormat`	`SearchWithFormat(query, format string) (string, error)`	`composer search query --format=FMT`
`SearchOnlyName`	`SearchOnlyName(query string) (string, error)`	`composer search query --only-name`
`SearchWithType`	`SearchWithType(query, packageType string) (string, error)`	`composer search query --type=TYPE`
✨ `SearchInfo`	`SearchInfo(query string) (*SearchResult, error)`	`composer search query --format=json` (structured)
📈 `BumpPackages`	`BumpPackages(packages []string) error`	`composer bump [packages...]`
`BumpPackagesWithOptions`	`BumpPackagesWithOptions(packages []string, options map[string]string) error`	`composer bump [options] [packages...]`
🔁 `Reinstall`	`Reinstall(packageName string) error`	`composer reinstall pkg`
`ReinstallWithOptions`	`ReinstallWithOptions(packageName string, options map[string]string) error`	`composer reinstall [options] pkg`
`ReinstallMultiple`	`ReinstallMultiple(packages []string) error`	`composer reinstall pkg1 pkg2 ...`
`ReinstallMultipleWithOptions`	`ReinstallMultipleWithOptions(packages []string, options map[string]string) error`	`composer reinstall [options] pkg1 ...`
🌍 `BrowsePackage`	`BrowsePackage(packageName string) error`	`composer browse pkg`
`BrowsePackageWithOptions`	`BrowsePackageWithOptions(packageName string, options map[string]string) error`	`composer browse pkg [options]`

✨ marked methods return structured Go types instead of raw strings; see the "Structured Return Values" section below.

➕ `RequirePackage`

Add a new dependency package to the project, write it to composer.json, and install immediately.

Signature

func (c *Composer) RequirePackage(packageName string, version string, dev bool) error

Parameters

Parameter	Type	Description
`packageName`	`string`	Package name, e.g., `"symfony/console"`
`version`	`string`	Version constraint, e.g., `"^5.0"`; empty means latest version
`dev`	`bool`	`true` adds as dev dependency (`--dev`)

Return Values

Type	Description
`error`	On failure, returns error wrapping `ErrRequirePackageFailed`

Example

// Add production dependency
err := comp.RequirePackage("symfony/console", "^5.0", false)
if err != nil {
	log.Fatalf("Failed to add dependency: %v", err)
}

// Add dev dependency
err = comp.RequirePackage("phpunit/phpunit", "^9.0", true)

Advanced

To add multiple packages at once, use RequireMultiple(map[string]string{"symfony/console": "^5.0", "monolog/monolog": "^2.0"}, false).
To dry-run without modifying composer.json, use RequireDryRun(packageName, version).
For more options (like --prefer-source, --no-update), use RequirePackageWithOptions.

➖ `Remove`

Remove the specified dependency package from the project.

Signature

func (c *Composer) Remove(packageName string, dev bool) error

Parameters

Parameter	Type	Description
`packageName`	`string`	Package name to remove
`dev`	`bool`	`true` removes from dev dependencies (`--dev`)

Example

// Remove production dependency
err := comp.Remove("symfony/console", false)

// Remove dev dependency
err = comp.Remove("phpunit/phpunit", true)

Advanced

Batch remove with RemoveMultiple([]string{"a/b", "c/d"}, false).
Dry-run with RemoveDryRun(packageName).

🔎 `ShowPackage` / ✨ `ShowPackageInfo`

Show detailed info of a specified package (version, dependencies, install location, etc.).

Signatures

func (c *Composer) ShowPackage(packageName string) (string, error)
func (c *Composer) ShowPackageInfo(packageName string) (*PackageInfo, error)

Parameters

Parameter	Type	Description
`packageName`	`string`	Package name to show info for

Return Values

ShowPackage: (string, error) — composer raw text output; returns ErrShowPackageFailed on failure.
ShowPackageInfo: (*PackageInfo, error) — parsed struct (internally executes composer show pkg --format=json).

Example

// Raw text
output, err := comp.ShowPackage("symfony/console")
fmt.Println(output)

// Structured
info, err := comp.ShowPackageInfo("symfony/console")
if err != nil {
	log.Fatalf("Failed to get package info: %v", err)
}
fmt.Printf("Package %s version %s\n", info.Name, info.Version)
fmt.Printf("Type: %s, Homepage: %s\n", info.Type, info.Homepage)
fmt.Printf("License: %v\n", info.License)

Advanced

For custom (non-json) output format, use ShowPackageWithFormat(packageName, format).
To view all installed packages, use ShowAllPackages(); for direct dependencies only, use ShowDirectPackages().

🌐 `Search` / ✨ `SearchInfo`

Search for packages matching keywords on Packagist.

Signatures

func (c *Composer) Search(query string) (string, error)
func (c *Composer) SearchInfo(query string) (*SearchResult, error)

Parameters

Parameter	Type	Description
`query`	`string`	Search keywords

Return Values

Search: (string, error) — raw text; returns ErrSearchFailed on failure.
SearchInfo: (*SearchResult, error) — structured result (internally executes composer search query --format=json).

Example

// Structured search
res, err := comp.SearchInfo("logger")
if err != nil {
	log.Fatalf("Search failed: %v", err)
}
for _, r := range res.Results {
	fmt.Printf("%s: %s\n", r.Name, r.Description)
}

Advanced

For exact name match only, use SearchOnlyName(query), reducing noise from descriptions.
For type filtering, use SearchWithType(query, "composer-plugin"), supporting types like library/composer-plugin/project.
For custom output format, use SearchWithFormat(query, "json").

⬆️ `OutdatedPackages` / ✨ `GetOutdatedInfo`

Show all outdated packages in the project and available updates.

Signatures

func (c *Composer) OutdatedPackages() (string, error)
func (c *Composer) GetOutdatedInfo() (*OutdatedResult, error)
func (c *Composer) GetOutdatedInfoWithOptions(options map[string]string) (*OutdatedResult, error)

Return Values

OutdatedPackages: (string, error) — raw text.
GetOutdatedInfo: (*OutdatedResult, error) — structured result (internally executes composer outdated --format=json).

Example

// Structured query of outdated packages
outdated, err := comp.GetOutdatedInfo()
if err != nil {
	log.Fatalf("Failed to get outdated package info: %v", err)
}
for _, p := range outdated.Installed {
	fmt.Printf("⬆️  %s: %s -> %s (%s)\n",
		p.Name, p.Installed, p.Latest, p.LatestStatus)
}
fmt.Printf("Total %d outdated packages\n", outdated.Count)

Advanced

For direct dependencies only, use OutdatedPackagesDirect().
For minor version updates only, use ShowOutdatedMinorOnly().
For custom options, use OutdatedWithOptions(map[string]string{"direct": "", "minor-only": ""}) or GetOutdatedInfoWithOptions.
For custom format, use OutdatedWithFormat("json") / ShowOutdatedWithFormat("text").

About Exit Codes

composer outdated may return non-zero exit code when there are outdated packages, but the output still contains valid JSON. GetOutdatedInfo handles this: when err != nil but output == "", it returns an empty result instead of an error.

🌳 `ShowDependencyTree`

Display a package's dependency relationships as a tree structure.

Signature

func (c *Composer) ShowDependencyTree(packageName string) (string, error)

Parameters

Parameter	Type	Description
`packageName`	`string`	Package name; empty string shows the entire project's dependency tree

Example

// Entire project's dependency tree
output, err := comp.ShowDependencyTree("")

// Specific package's dependency tree
output, err = comp.ShowDependencyTree("symfony/console")

Advanced

To parse the tree into Go structs, use ParseDependencyTreeJSON(output) in parsing.go, which returns []DependencyNode, each node has Name, Version, Children.

❓ `WhyPackage` / 🚫 `WhyNotPackage` / 🔗 `ShowReverseDependencies`

These three method groups are for understanding dependency relationships:

Method	Signature	Equivalent Command	Purpose
`WhyPackage`	`WhyPackage(packageName string) (string, error)`	`composer why pkg`	Explain why a package is installed (depended on by whom)
`WhyNotPackage`	`WhyNotPackage(packageName, version string) (string, error)`	`composer why-not pkg ver`	Explain why a version can't be installed (conflict source)
`ShowReverseDependencies`	`ShowReverseDependencies(packageName string) (string, error)`	`composer depends pkg`	Show which installed packages depend on this one

Example

// Why is polyfill-mbstring installed?
why, _ := comp.WhyPackage("symfony/polyfill-mbstring")
fmt.Println("Install reason:", why)

// Why can't symfony/console v4.0.0 be installed?
whyNot, _ := comp.WhyNotPackage("symfony/console", "v4.0.0")
fmt.Println("Reason it can't be installed:", whyNot)

// Who depends on polyfill-mbstring?
deps, _ := comp.ShowReverseDependencies("symfony/polyfill-mbstring")
fmt.Println("Reverse dependencies:", deps)

Advanced

All three have WithOptions variants: WhyWithOptions, WhyNotWithOptions, DependsWithOptions, accepting options like map[string]string{"format": "json"}.

📈 `BumpPackages`

Upgrade specified packages to the latest version matching the version constraint in composer.json (doesn't change constraints, only updates lock versions). Requires Composer 2.4+.

Signatures

func (c *Composer) BumpPackages(packages []string) error
func (c *Composer) BumpPackagesWithOptions(packages []string, options map[string]string) error

Parameters

Parameter	Type	Description
`packages`	`[]string`	List of package names to bump; empty slice bumps all packages

Example

// Bump multiple packages
err := comp.BumpPackages([]string{"symfony/console", "symfony/process"})
if err != nil {
	log.Fatalf("Failed to bump packages: %v", err)
}

// Bump all packages
err = comp.BumpPackages([]string{})

// With options (dev-only + dry-run)
options := map[string]string{
	"dev-only":      "",
	"prefer-stable": "",
	"dry-run":       "",
}
err = comp.BumpPackagesWithOptions([]string{"symfony/console"}, options)

🔁 `Reinstall`

Reinstall specified packages using Composer 2.2+'s native reinstall command.

Signatures

func (c *Composer) Reinstall(packageName string) error
func (c *Composer) ReinstallWithOptions(packageName string, options map[string]string) error
func (c *Composer) ReinstallMultiple(packages []string) error
func (c *Composer) ReinstallMultipleWithOptions(packages []string, options map[string]string) error

Example

// Reinstall single package
err := comp.Reinstall("symfony/console")

// Reinstall with prefer-source
err = comp.ReinstallWithOptions("symfony/console", map[string]string{"prefer-source": ""})

// Batch reinstall
err = comp.ReinstallMultiple([]string{"symfony/console", "symfony/process"})

Version Requirement

The reinstall command requires Composer 2.2 or higher. For older versions, use Remove + RequirePackage as a substitute.

🌍 `BrowsePackage`

Open the specified package's project page (usually the GitHub repository) in the default browser.

Signatures

func (c *Composer) BrowsePackage(packageName string) error
func (c *Composer) BrowsePackageWithOptions(packageName string, options map[string]string) error

Example

// Open package homepage
err := comp.BrowsePackage("symfony/console")

// Open docs page
err = comp.BrowsePackageWithOptions("symfony/console", map[string]string{"docs": ""})

// Open issue tracker page
err = comp.BrowsePackageWithOptions("symfony/console", map[string]string{"issues": ""})

Environment Dependency

Requires OS support for opening a browser, and the package must declare a project URL in composer.json. Server environments without GUI are generally not applicable.

🧱 Structured Return Values

Structured methods for package operations return the following types (all defined in result_types.go):

`PackageInfo` (returned by `ShowPackageInfo`)

type PackageInfo struct {
	Name        string                 `json:"name"`
	Version     string                 `json:"version"`
	Description string                 `json:"description,omitempty"`
	Type        string                 `json:"type,omitempty"`
	Keywords    []string               `json:"keywords,omitempty"`
	Homepage    string                 `json:"homepage,omitempty"`
	License     []string               `json:"license,omitempty"`
	Authors     []PackageAuthor        `json:"authors,omitempty"`
	Support     map[string]string      `json:"support,omitempty"`
	Require     map[string]string      `json:"require,omitempty"`
	RequireDev  map[string]string      `json:"require_dev,omitempty"`
	Autoload    map[string]interface{} `json:"autoload,omitempty"`
	Source      PackageSource          `json:"source,omitempty"`
	Dist        PackageDist            `json:"dist,omitempty"`
	Abandoned   interface{}            `json:"abandoned,omitempty"` // bool or string
	Time        string                 `json:"time,omitempty"`
}

`OutdatedResult` (returned by `GetOutdatedInfo`)

type OutdatedResult struct {
	Installed []OutdatedPackage `json:"installed"`
	Count     int               `json:"count,omitempty"`
}

type OutdatedPackage struct {
	Name         string      `json:"name"`
	Latest       string      `json:"latest"`
	Installed    string      `json:"version"`
	LatestStatus string      `json:"latest_status"` // "semver-safe-update" | "update-possible" | "up-to-date"
	Abandoned    interface{} `json:"abandoned,omitempty"`
}

`SearchResult` (returned by `SearchInfo`)

type SearchResult struct {
	Results []SearchResultItem `json:"results"`
	Total   int                `json:"total,omitempty"`
}

type SearchResultItem struct {
	Name        string `json:"name"`
	Description string `json:"description,omitempty"`
	URL         string `json:"url,omitempty"`
	Repository  string `json:"repository,omitempty"`
}

When to Use Structured Variants

When you need to programmatically check version numbers, count outdated packages, store search results in a database, or render to UI, definitely use ShowPackageInfo / GetOutdatedInfo / SearchInfo. Raw string methods are only suitable for human reading or log output.

🧭 Next Steps

📦 Dependencies — Install / Update / DumpAutoload
🛠️ Core Runtime — Run / RunWithContext
🧩 Convenience Queries — Higher-level wrappers like IsPackageInstalled / GetDirectDependencyNames

🔍 Packages ​

🎯 When to Use ​

📋 Method Overview ​

➕ RequirePackage ​

Signature ​

Parameters ​

Return Values ​

Example ​

Advanced ​

➖ Remove ​

Signature ​

Parameters ​

Example ​

Advanced ​

🔎 ShowPackage / ✨ ShowPackageInfo ​

Signatures ​

Parameters ​

Return Values ​

Example ​

Advanced ​

🌐 Search / ✨ SearchInfo ​

Signatures ​

Parameters ​

Return Values ​

Example ​

Advanced ​

⬆️ OutdatedPackages / ✨ GetOutdatedInfo ​

Signatures ​

Return Values ​

Example ​

Advanced ​

🌳 ShowDependencyTree ​

Signature ​

Parameters ​

Example ​

Advanced ​

❓ WhyPackage / 🚫 WhyNotPackage / 🔗 ShowReverseDependencies ​

Example ​

Advanced ​

📈 BumpPackages ​

Signatures ​

Parameters ​

Example ​

🔁 Reinstall ​

Signatures ​

Example ​

🌍 BrowsePackage ​

Signatures ​

Example ​

🧱 Structured Return Values ​

PackageInfo (returned by ShowPackageInfo) ​

OutdatedResult (returned by GetOutdatedInfo) ​

SearchResult (returned by SearchInfo) ​

🧭 Next Steps ​

🔍 Packages

🎯 When to Use

📋 Method Overview

➕ `RequirePackage`

Signature

Parameters

Return Values

Example

Advanced

➖ `Remove`

Signature

Parameters

Example

Advanced

🔎 `ShowPackage` / ✨ `ShowPackageInfo`

Signatures

Parameters

Return Values

Example

Advanced

🌐 `Search` / ✨ `SearchInfo`

Signatures

Parameters

Return Values

Example

Advanced

⬆️ `OutdatedPackages` / ✨ `GetOutdatedInfo`

Signatures

Return Values

Example

Advanced

🌳 `ShowDependencyTree`

Signature

Parameters

Example

Advanced

❓ `WhyPackage` / 🚫 `WhyNotPackage` / 🔗 `ShowReverseDependencies`

Example

Advanced

📈 `BumpPackages`

Signatures

Parameters

Example

🔁 `Reinstall`

Signatures

Example

🌍 `BrowsePackage`

Signatures

Example

🧱 Structured Return Values

`PackageInfo` (returned by `ShowPackageInfo`)

`OutdatedResult` (returned by `GetOutdatedInfo`)

`SearchResult` (returned by `SearchInfo`)

🧭 Next Steps