Add check for npm dependencies

checks/Readme.md

@@ -4,7 +4,7 @@ This Go package is for all of the checks that localstatus can perform.
 Each check is named with a loose hierarchy.
 
 Checks conform to the `Check` interface, which is defined in
-the `check.go` file.
+the `interface.go` file.
 
 Eventually, there will be many checks.
 

checks/check.npm.install.go

@@ -0,0 +1,44 @@
+package checks
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+/*
+check = "npm.install"
+
+Passes if npm dependencies are installed.
+This is implemented with the `npm ls` command,
+so npm must be installed and on the PATH already.
+
+  - package: A string with the path to a package.json file.
+*/
+type CheckNpmInstall struct{}
+
+func (n CheckNpmInstall) Run(p Params) CheckResult {
+	packageFile := p.GetString("package")
+
+	_, err := os.Lstat(packageFile)
+	if os.IsNotExist(err) {
+		return newBasicResult(false, packageFile+" does not exist")
+	}
+
+	dir := filepath.Dir(packageFile)
+
+	cmd := exec.Command("npm", "ls")
+	cmd.Dir = dir
+	err = cmd.Start()
+	if err != nil {
+		return newBasicResult(false, fmt.Sprintf("npm in %s: %s", dir, err))
+	}
+
+	err = cmd.Wait()
+	if err != nil {
+		return newBasicResult(false, packageFile+" dependencies not satisfied")
+	}
+
+	return newBasicResult(true, packageFile+" dependencies")
+}

checks/checkregistry.go

@@ -33,5 +33,6 @@ func (c *CheckRegistry) AddAllChecks() {
 	c.Add("file.exists", CheckFileExists{})
 	c.Add("git.branch", CheckGitBranch{})
 	c.Add("http.ok", CheckHttpOk{})
+	c.Add("npm.install", CheckNpmInstall{})
 	c.Add("tcp.open", CheckTcpOpen{})
 }

docs/all.md

@@ -72,6 +72,16 @@ Passes if the URL responds with 200 OK. Uses the GET method.
 
 ----------
 
+check = "npm.install"
+
+Passes if npm dependencies are installed.
+This is implemented with the `npm ls` command,
+so npm must be installed and on the PATH already.
+
+  - package: A string with the path to a package.json file.
+
+----------
+
 check = "tcp.open"
 
 Passes if a TCP connection can be opened.

docs/npm.install.md

@@ -0,0 +1,7 @@
+check = "npm.install"
+
+Passes if npm dependencies are installed.
+This is implemented with the `npm ls` command,
+so npm must be installed and on the PATH already.
+
+  - package: A string with the path to a package.json file.