Fix activated_path_skip on repeated running of emsdk_env.sh

.circleci/config.yml

@@ -80,6 +80,7 @@ jobs:
       - run:
           name: Install debian packages
           command: apt-get update -q && apt-get install -q -y cmake build-essential openjdk-8-jre-headless ksh zsh
+      - run: test/test_node_path.sh
       - run: test/test.sh
       - run: test/test_source_env.sh
       - run:

emsdk.py

@@ -1438,9 +1438,18 @@ def get_required_path(active_tools):
   path_add = [to_native_path(EMSDK_PATH)]
   for tool in active_tools:
     if hasattr(tool, 'activated_path'):
-      if hasattr(tool, 'activated_path_skip') and which(tool.activated_path_skip):
-        continue
       path = to_native_path(tool.expand_vars(tool.activated_path))
+      # If the tool has an activated_path_skip attribute then we don't add
+      # the tools path to the users path if a program by that name is found
+      # in the existing PATH.  This allows us to, for example, add our version
+      # node to the users PATH if, and only if, they don't already have a
+      # another version of node in thier PATH.
+      if hasattr(tool, 'activated_path_skip'):
+        current_path = which(tool.activated_path_skip)
+        # We found an executable by this name in the current PATH, but we
+        # ignore our own version for this purpose.
+        if current_path and os.path.dirname(current_path) != path:
+          continue
       path_add.append(path)
   return path_add
 

test/test_node_path.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+echo "Test that node is added to that PATH if, and only if, it is not one already present".
+
+if [ -n "$EMSDK" ]; then
+    echo "EMSDK is already defined in this shell. Run tests in a shell without sourcing emsdk_env.sh first"
+    exit 1
+fi
+
+DIR=$(dirname "$BASH_SOURCE")
+cd $DIR/..
+
+./emsdk install latest
+./emsdk activate latest
+
+if which node; then
+  echo "Test should be run without node in the path"
+  exit 1
+fi
+
+# Run emsdk_env.sh and confirm that node was added to the PATH
+. emsdk_env.sh
+
+if ! which node; then
+  echo "node not found in path after emsdk_env.sh"
+  exit 1
+fi
+
+# Run emsdk_env.sh again and confirm that node is still in the PATH
+. emsdk_env.sh
+
+if ! which node; then
+  echo "node not found in path after emsdk_env.sh"
+  exit 1
+fi