improve tests: add tests, add js, vm testing

tests/stdlib/tosenv.nim

@@ -1,42 +1,58 @@
 discard """
   matrix: "--threads"
   joinable: false
-  targets: "c cpp"
+  targets: "c js cpp"
 """
-import os
-
-block: # delEnv
-  const dummyEnvVar = "D20210720T144752" # This env var wouldn't be likely to exist to begin with
-  doAssert not existsEnv(dummyEnvVar)
-  putEnv(dummyEnvVar, "1")
-  doAssert existsEnv(dummyEnvVar)  
-  delEnv(dummyEnvVar)
-  doAssert not existsEnv(dummyEnvVar)
-  delEnv(dummyEnvVar) # deleting an already deleted env var
-  doAssert not existsEnv(dummyEnvVar)
-
-block: # putEnv
-  # raises OSError on invalid input
-  doAssertRaises(OSError, putEnv("NIM_TESTS_TOSENV_PUT=DUMMY_VALUE", "NEW_DUMMY_VALUE"))
-  doAssertRaises(OSError, putEnv("", "NEW_DUMMY_VALUE"))
-  doAssert not existsEnv("")
-  doAssert not existsEnv("NIM_TESTS_TOSENV_PUT=DUMMY_VALUE")
-  doAssert not existsEnv("NIM_TESTS_TOSENV_PUT")
-
-block:
-  doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", "") == ""
-  doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", " ") == " "
-  doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", "Arrakis") == "Arrakis"
-
-block: # bug #18533
-  proc c_getenv(env: cstring): cstring {.importc: "getenv", header: "<stdlib.h>".}
-  var thr: Thread[void]
-  proc threadFunc {.thread.} = putEnv("foo", "fooVal2")
-
-  putEnv("foo", "fooVal1")
-  doAssert getEnv("foo") == "fooVal1"
-  createThread(thr, threadFunc)
-  joinThreads(thr)
-  doAssert getEnv("foo") == $c_getenv("foo")
-
-  doAssertRaises(OSError): delEnv("foo=bar")
+
+import std/os
+from std/sequtils import toSeq
+import stdtest/testutils
+
+template main =
+  block: # delEnv, existsEnv, getEnv, envPairs
+    for val in ["val", ""]: # ensures empty val works too
+      const key = "NIM_TESTS_TOSENV_KEY"
+      doAssert not existsEnv(key)
+      putEnv(key, val)
+      doAssert existsEnv(key)
+      doAssert getEnv(key) == val
+      when nimvm: discard
+      else:
+        doAssert (key, val) in toSeq(envPairs())
+      delEnv(key)
+      when nimvm: discard
+      else:
+        doAssert (key, val) notin toSeq(envPairs())
+      doAssert not existsEnv(key)
+      delEnv(key) # deleting an already deleted env var
+      doAssert not existsEnv(key)
+
+    block:
+      doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", "") == ""
+      doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", " ") == " "
+      doAssert getEnv("NIM_TESTS_TOSENV_NONEXISTENT", "defval") == "defval"
+
+    whenVMorJs: discard # xxx improve
+    do:
+      doAssertRaises(OSError, putEnv("NIM_TESTS_TOSENV_PUT=DUMMY_VALUE", "NEW_DUMMY_VALUE"))
+      doAssertRaises(OSError, putEnv("", "NEW_DUMMY_VALUE"))
+      doAssert not existsEnv("")
+      doAssert not existsEnv("NIM_TESTS_TOSENV_PUT=DUMMY_VALUE")
+      doAssert not existsEnv("NIM_TESTS_TOSENV_PUT")
+
+static: main()
+main()
+
+when not defined(js):
+  block: # bug #18533
+    proc c_getenv(env: cstring): cstring {.importc: "getenv", header: "<stdlib.h>".}
+    var thr: Thread[void]
+    proc threadFunc {.thread.} = putEnv("foo", "fooVal2")
+
+    putEnv("foo", "fooVal1")
+    doAssert getEnv("foo") == "fooVal1"
+    createThread(thr, threadFunc)
+    joinThreads(thr)
+    doAssert getEnv("foo") == $c_getenv("foo")
+
+    doAssertRaises(OSError): delEnv("foo=bar")