Add --node-version config to override engine checking

Set to null to disable engine checking altogether, or some semver
string to use that instead of the actual version.

7 files changed, 49 insertions, 3 deletions

diff --git a/doc/config.md b/doc/config.md
index 010691bf7..14621de0c 100644
--- a/doc/config.md
+++ b/doc/config.md
@@ -360,3 +360,12 @@ default, `npm install foo` will fetch and install the latest version of
 Default: true
 
 Show the package description in npm ls.
+
+## node-version
+
+Default: `process.version` from the node environment
+
+An effective version of node to use when checking for "engines"
+compliance.
+
+Set to null or false to suppress engine checking altogether.
diff --git a/lib/utils/default-config.js b/lib/utils/default-config.js
index 8d43307b2..cd0714a18 100644
--- a/lib/utils/default-config.js
+++ b/lib/utils/default-config.js
@@ -38,6 +38,7 @@ module.exports =
   , loglevel : "info"
   , manroot : path.join(process.execPath, "..", "..", "share", "man")
   , "must-install" : true
+  , "node-version" : process.version
   , outfd : stdio.stdoutFD
   , proxy : process.env.http_proxy || null
   , prune : undefined // if set to boolean false, then that means "never"
diff --git a/lib/utils/parse-args.js b/lib/utils/parse-args.js
index fbd9914b7..d3d769092 100644
--- a/lib/utils/parse-args.js
+++ b/lib/utils/parse-args.js
@@ -33,6 +33,7 @@ exports.types =
   , loglevel : ["silent","win","error","warn","info","verbose","silly"]
   , manroot : path
   , "must-install" : Boolean
+  , "node-version" : String
   , outfd : [Number, Stream]
   , proxy : url
   , prune : Boolean
@@ -71,6 +72,7 @@ exports.shorthands =
   , "no-rb" : ["--no-rebuild-bundle"]
   , desc : ["--description"]
   , "no-desc" : ["--no-description"]
+  , "nv" : "--node-version"
   }
 
 
diff --git a/lib/utils/read-json.js b/lib/utils/read-json.js
index 22c3054c5..816da1d04 100644
--- a/lib/utils/read-json.js
+++ b/lib/utils/read-json.js
@@ -218,8 +218,9 @@ function testEngine (json) {
     } else json.engines = [ json.engines ]
   }
 
-  var nodeVer = process.version.replace(/\+$/, '')
+  var nodeVer = npm.config.get("node-version")
     , ok = false
+  if (nodeVer) nodeVer = nodeVer.replace(/\+$/, '')
   if (Array.isArray(json.engines)) {
     // Packages/1.0 commonjs style, with an array.
     // hack it to just hang a "node" member with the version range,
@@ -236,10 +237,13 @@ function testEngine (json) {
   if (json.engines.node === "") json.engines.node = "*"
   if (json.engines.node && null === semver.validRange(json.engines.node)) {
     log.warn( json.engines.node
-            , "not a valid range.  Please see `npm help json`" )
+            , "Invalid range in engines.node.  Please see `npm help json`" )
   }
 
-  json._engineSupported = semver.satisfies(nodeVer, json.engines.node||"null")
+  if (nodeVer) {
+    json._engineSupported = semver.satisfies( nodeVer
+                                            , json.engines.node || "null" )
+  }
   if (json.engines.hasOwnProperty("npm") && json._engineSupported) {
     json._engineSupported = semver.satisfies(npm.version, json.engines.npm)
   }
diff --git a/man1/config.1 b/man1/config.1
index adc330b5a..15fe8385a 100644
--- a/man1/config.1
+++ b/man1/config.1
@@ -460,3 +460,13 @@ Default: true
 .
 .P
 Show the package description in npm ls\.
+.
+.SH "node\-version"
+Default: \fBprocess\.version\fR from the node environment
+.
+.P
+An effective version of node to use when checking for "engines"
+compliance\.
+.
+.P
+Set to null or false to suppress engine checking altogether\.
diff --git a/man1/get.1 b/man1/get.1
index adc330b5a..15fe8385a 100644
--- a/man1/get.1
+++ b/man1/get.1
@@ -460,3 +460,13 @@ Default: true
 .
 .P
 Show the package description in npm ls\.
+.
+.SH "node\-version"
+Default: \fBprocess\.version\fR from the node environment
+.
+.P
+An effective version of node to use when checking for "engines"
+compliance\.
+.
+.P
+Set to null or false to suppress engine checking altogether\.
diff --git a/man1/set.1 b/man1/set.1
index adc330b5a..15fe8385a 100644
--- a/man1/set.1
+++ b/man1/set.1
@@ -460,3 +460,13 @@ Default: true
 .
 .P
 Show the package description in npm ls\.
+.
+.SH "node\-version"
+Default: \fBprocess\.version\fR from the node environment
+.
+.P
+An effective version of node to use when checking for "engines"
+compliance\.
+.
+.P
+Set to null or false to suppress engine checking altogether\.