Add Rust backend

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/natefinch/atomic v0.0.0-20150920032501-a62ce929ffcc
 	github.com/rakyll/statik v0.1.6
 	github.com/spf13/cobra v0.0.5
+	github.com/stretchr/testify v1.7.0 // indirect
 	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550
 	golang.org/x/tools v0.0.0-20200605181038-cef9fc3bc8f0 // indirect
 	gopkg.in/yaml.v2 v2.2.2

go.sum

@@ -7,6 +7,8 @@ github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
@@ -27,6 +29,7 @@ github.com/natefinch/atomic v0.0.0-20150920032501-a62ce929ffcc h1:7xGrl4tTpBQu5Z
 github.com/natefinch/atomic v0.0.0-20150920032501-a62ce929ffcc/go.mod h1:1rLVY/DWf3U6vSZgH16S7pymfrhK2lcUlXjgGglw/lY=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rakyll/statik v0.1.6 h1:uICcfUXpgqtw2VopbIncslhAmE5hwc4g20TEyEENBNs=
 github.com/rakyll/statik v0.1.6/go.mod h1:OEi9wJV/fMUAGx1eNjq75DKDsJVuEv1U0oYdX6GX8Zs=
@@ -43,7 +46,10 @@ github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/viper v1.3.2 h1:VUFqw5KcqRf7i70GOzW7N+Q7+gxVBkSSqiXB12+JQ4M=
 github.com/spf13/viper v1.3.2/go.mod h1:ZiWeW+zYFKm7srdB9IoDzzZXaJaI5eL9QjNiN/DMA2s=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -76,3 +82,5 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/backends/backends.go

@@ -14,6 +14,7 @@ import (
 	"github.com/replit/upm/internal/backends/python"
 	"github.com/replit/upm/internal/backends/rlang"
 	"github.com/replit/upm/internal/backends/ruby"
+	"github.com/replit/upm/internal/backends/rust"
 	"github.com/replit/upm/internal/util"
 )
 
@@ -33,6 +34,7 @@ var languageBackends = []api.LanguageBackend{
 	java.JavaBackend,
 	rlang.RlangBackend,
 	dotnet.DotNetBackend,
+	rust.RustBackend,
 }
 
 // matchesLanguage checks if a language backend matches a value for

internal/backends/backends_test.go

@@ -14,7 +14,9 @@ func TestGetBackends(t *testing.T) {
 		"Setup.fs":       "dotnet",
 		"project.fsproj": "dotnet",
 		"pom.xml":        "java-maven",
-		"package.json":   "nodejs-npm"}
+		"package.json":   "nodejs-npm",
+		"Cargo.toml":     "rust",
+	}
 
 	dir, err := ioutil.TempDir("", "TestGetBackends")
 	if err != nil {

internal/backends/rust/rust.go

@@ -0,0 +1,259 @@
+// Package rust provides a backend for Rust using Cargo.
+package rust
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+
+	"github.com/BurntSushi/toml"
+	"github.com/replit/upm/internal/api"
+	"github.com/replit/upm/internal/util"
+)
+
+type cargoToml struct {
+	Dependencies map[string]interface{} `toml:"dependencies"`
+}
+
+type cargoLock struct {
+	Packages []cargoPackage `toml:"package"`
+}
+
+type cargoPackage struct {
+	Name    string `toml:"name"`
+	Version string `toml:"version"`
+}
+
+type crateSearchResults struct {
+	Crates []crate `json:"crates"`
+}
+
+type crateInfoResult struct {
+	Crate    crate     `json:"crate"`
+	Versions []version `json:"versions"`
+}
+
+type crate struct {
+	Name          string `json:"name"`
+	Description   string `json:"description"`
+	Homepage      string `json:"homepage"`
+	Documentation string `json:"documentation"`
+	Repository    string `json:"repository"`
+	NewestVersion string `json:"newest_version"`
+	Versions      []int  `json:"versions"`
+}
+
+type version struct {
+	Num         string `json:"num"`
+	PublishedBy user   `json:"published_by"`
+	License     string `json:"license"`
+}
+
+type user struct {
+	Name string `json:"name"`
+}
+
+func (c *crateInfoResult) toPkgInfo() api.PkgInfo {
+	var author string
+	var license string
+
+	for _, version := range c.Versions {
+		if version.Num == c.Crate.NewestVersion {
+			author = version.PublishedBy.Name
+			license = version.License
+			break
+		}
+	}
+
+	return api.PkgInfo{
+		Name:             c.Crate.Name,
+		Description:      c.Crate.Description,
+		Version:          c.Crate.NewestVersion,
+		HomepageURL:      c.Crate.Homepage,
+		DocumentationURL: c.Crate.Documentation,
+		SourceCodeURL:    c.Crate.Repository,
+		Author:           author,
+		License:          license,
+	}
+}
+
+func search(query string) []api.PkgInfo {
+	endpoint := "https://crates.io/api/v1/crates"
+	path := "?q=" + url.QueryEscape(query)
+
+	resp, err := http.Get(endpoint + path)
+	if err != nil {
+		util.Die("crates.io: %s", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		util.Die("crates.io: %s", err)
+	}
+
+	var crateResults crateSearchResults
+	if err := json.Unmarshal(body, &crateResults); err != nil {
+		util.Die("crates.io: %s", err)
+	}
+
+	var pkgs []api.PkgInfo
+	for _, crate := range crateResults.Crates {
+		crateInfo := crateInfoResult{
+			Crate: crate,
+		}
+		pkgs = append(pkgs, crateInfo.toPkgInfo())
+	}
+
+	return pkgs
+}
+
+func info(name api.PkgName) api.PkgInfo {
+	endpoint := "https://crates.io/api/v1/crates"
+	path := "/" + url.PathEscape(string(name))
+
+	resp, err := http.Get(endpoint + path)
+	if err != nil {
+		util.Die("crates.io: %s", err)
+	}
+	defer resp.Body.Close()
+
+	switch resp.StatusCode {
+	case 200:
+		break
+	case 404:
+		return api.PkgInfo{}
+	default:
+		util.Die("crates.io: HTTP status %d", resp.StatusCode)
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	var crateInfo crateInfoResult
+	if err := json.Unmarshal(body, &crateInfo); err != nil {
+		util.Die("crates.io: %s", err)
+	}
+
+	return crateInfo.toPkgInfo()
+}
+
+func listSpecfile() map[api.PkgName]api.PkgSpec {
+	contents, err := ioutil.ReadFile("Cargo.toml")
+	if err != nil {
+		util.Die("Cargo.toml: %s", err)
+	}
+
+	return listSpecfileWithContents(contents)
+}
+
+func listSpecfileWithContents(contents []byte) map[api.PkgName]api.PkgSpec {
+	var specfile cargoToml
+	err := toml.Unmarshal(contents, &specfile)
+	if err != nil {
+		util.Die("Cargo.toml: %s", err)
+	}
+
+	packages := make(map[api.PkgName]api.PkgSpec)
+	for name, dependency := range specfile.Dependencies {
+		var spec api.PkgSpec
+		switch value := dependency.(type) {
+		case string:
+			spec = api.PkgSpec(value)
+
+		case map[string]interface{}:
+			found := false
+			for _, key := range []string{"version", "git", "path"} {
+				specStr, ok := value[key].(string)
+				if !ok {
+					continue
+				}
+
+				spec = api.PkgSpec(specStr)
+				found = true
+				break
+			}
+
+			if !found {
+				util.Die("Cargo.toml: could not determine spec for dependecy %q", name)
+			}
+
+		default:
+			util.Die("Cargo.toml: unexpected dependency format %q", name)
+		}
+
+		packages[api.PkgName(name)] = spec
+
+	}
+
+	return packages
+}
+
+func listLockfile() map[api.PkgName]api.PkgVersion {
+	contents, err := ioutil.ReadFile("Cargo.lock")
+	if err != nil {
+		util.Die("Cargo.lock: %s", err)
+	}
+
+	return listLockfileWithContents(contents)
+}
+
+func listLockfileWithContents(contents []byte) map[api.PkgName]api.PkgVersion {
+	var lockfile cargoLock
+	err := toml.Unmarshal(contents, &lockfile)
+	if err != nil {
+		util.Die("Cargo.lock: %s", err)
+	}
+
+	packages := make(map[api.PkgName]api.PkgVersion)
+	for _, pkg := range lockfile.Packages {
+		packages[api.PkgName(pkg.Name)] = api.PkgVersion(pkg.Version)
+	}
+
+	return packages
+}
+
+// RustBackend is a UPM backend for Rust that uses Cargo.
+var RustBackend = api.LanguageBackend{
+	Name:             "rust",
+	Specfile:         "Cargo.toml",
+	Lockfile:         "Cargo.lock",
+	FilenamePatterns: []string{"*.rs"},
+	GetPackageDir: func() string {
+		return "target"
+	},
+	Search: search,
+	Info:   info,
+	Add: func(pkgs map[api.PkgName]api.PkgSpec, projectName string) {
+		if !util.Exists("Cargo.toml") {
+			util.RunCmd([]string{"cargo", "init", "."})
+		}
+		cmd := []string{"cargo", "add"}
+		for name, spec := range pkgs {
+			arg := string(name)
+			if spec != "" {
+				arg += "@" + string(spec)
+			}
+			cmd = append(cmd, arg)
+		}
+		util.RunCmd(cmd)
+	},
+	Remove: func(pkgs map[api.PkgName]bool) {
+		cmd := []string{"cargo", "rm"}
+		for name := range pkgs {
+			cmd = append(cmd, string(name))
+		}
+		util.RunCmd(cmd)
+	},
+	Lock: func() {
+		// Lock file is updated at build time
+	},
+	Install: func() {
+		// Dependencies are installed at build time
+	},
+	ListSpecfile: listSpecfile,
+	ListLockfile: listLockfile,
+	Guess: func() (map[api.PkgName]bool, bool) {
+		util.NotImplemented()
+		return nil, false
+	},
+}