Added some comments on SemanticAnalyzer >> errorUnknownVariable:

js/Compiler-Semantic.js

@@ -1269,7 +1269,7 @@ _st(_st(_st(self["@currentScope"])._methodScope())._unknownVariables())._add_(_s
 };
 return self}, self, "errorUnknownVariable:", [aNode], smalltalk.SemanticAnalyzer)},
 args: ["aNode"],
-source: "errorUnknownVariable: aNode\x0a\x09\x22Throw an error if the variable is undeclared in the global JS scope (i.e. window)\x22\x0a\x0a\x09| identifier |\x0a    identifier := aNode value.\x0a\x09((#('jQuery' 'window' 'process' 'global') includes: identifier) not and: [ self isVariableGloballyUndefined: identifier ]) ifTrue: [\x0a\x09\x09\x09UnknownVariableError new\x0a\x09\x09\x09\x09variableName: aNode value;\x0a\x09\x09\x09\x09signal ]\x0a\x09\x09ifFalse: [\x0a\x09\x09\x09currentScope methodScope unknownVariables add: aNode value. ]",
+source: "errorUnknownVariable: aNode\x0a\x09\x22Throw an error if the variable is undeclared in the global JS scope (i.e. window).\x0a    We allow four variable names in addition: `jQuery`, `window`, `process` and `global` \x0a    for nodejs and browser environments. \x0a    \x0a    This is only to make sure compilation works on both browser-based and nodejs environments.\x0a    The ideal solution would be to use a pragma instead\x22\x0a\x0a\x09| identifier |\x0a    identifier := aNode value.\x0a    \x0a\x09((#('jQuery' 'window' 'process' 'global') includes: identifier) not \x0a        and: [ self isVariableGloballyUndefined: identifier ]) \x0a        \x09ifTrue: [\x0a\x09\x09\x09\x09UnknownVariableError new\x0a\x09\x09\x09\x09\x09variableName: aNode value;\x0a\x09\x09\x09\x09\x09signal ]\x0a\x09\x09\x09ifFalse: [\x0a\x09\x09\x09\x09currentScope methodScope unknownVariables add: aNode value ]",
 messageSends: ["value", "ifTrue:ifFalse:", "variableName:", "new", "signal", "add:", "unknownVariables", "methodScope", "and:", "isVariableGloballyUndefined:", "not", "includes:"],
 referencedClasses: ["UnknownVariableError"]
 }),

st/Compiler-Semantic.st

@@ -418,16 +418,24 @@ errorShadowingVariable: aString
 !
 
 errorUnknownVariable: aNode
-	"Throw an error if the variable is undeclared in the global JS scope (i.e. window)"
+	"Throw an error if the variable is undeclared in the global JS scope (i.e. window).
+    We allow four variable names in addition: `jQuery`, `window`, `process` and `global` 
+    for nodejs and browser environments. 
+    
+    This is only to make sure compilation works on both browser-based and nodejs environments.
+    The ideal solution would be to use a pragma instead"
 
 	| identifier |
     identifier := aNode value.
-	((#('jQuery' 'window' 'process' 'global') includes: identifier) not and: [ self isVariableGloballyUndefined: identifier ]) ifTrue: [
-			UnknownVariableError new
-				variableName: aNode value;
-				signal ]
-		ifFalse: [
-			currentScope methodScope unknownVariables add: aNode value. ]
+    
+	((#('jQuery' 'window' 'process' 'global') includes: identifier) not 
+        and: [ self isVariableGloballyUndefined: identifier ]) 
+        	ifTrue: [
+				UnknownVariableError new
+					variableName: aNode value;
+					signal ]
+			ifFalse: [
+				currentScope methodScope unknownVariables add: aNode value ]
 ! !
 
 !SemanticAnalyzer methodsFor: 'factory'!