feat(*): add environment variable and random functions

4 files changed, 205 insertions, 31 deletions

diff --git a/spec/01-time_spec.lua b/spec/01-time_spec.lua
new file mode 100644
index 0000000..80faa75
--- /dev/null
+++ b/spec/01-time_spec.lua
@@ -0,0 +1,77 @@
+local system = require 'system.core'
+
+describe('Test time functions', function()
+
+  -- returns the new second, on the new second
+  local function wait_for_second_rollover()
+    local start_time = math.floor(os.time())
+    local end_time = math.floor(os.time())
+    while end_time == start_time do
+      end_time = math.floor(os.time())
+    end
+    return end_time
+  end
+
+
+  describe("time()", function()
+
+    it('returns current time', function()
+      wait_for_second_rollover()
+      local expected_time = wait_for_second_rollover()
+      local received_time = system.gettime()
+      assert.is.near(expected_time, received_time, 0.02)
+
+      wait_for_second_rollover()
+      assert.is.near(1, system.gettime() - received_time, 0.02)
+    end)
+
+  end)
+
+
+
+  describe("monotime()", function()
+
+    it('returns monotonically increasing time', function()
+      local starttime = system.monotime()
+      local endtime = system.monotime()
+      local delta = endtime - starttime
+      assert.is_true(starttime > 0)
+      assert.is_true(delta >= 0)
+      assert.is_true(system.monotime() - endtime >= 0)
+    end)
+
+  end)
+
+
+
+  describe("sleep()", function()
+
+    it("should sleep for the specified time", function()
+      local start_time = system.gettime()
+      system.sleep(1, 1)
+      local end_time = system.gettime()
+      local elapsed_time = end_time - start_time
+      assert.is.near(elapsed_time, 1, 0.01)
+    end)
+
+
+    it("should sleep for the specified time; fractional", function()
+      local start_time = system.gettime()
+      system.sleep(0.5, 1)
+      local end_time = system.gettime()
+      local elapsed_time = end_time - start_time
+      assert.is.near(0.5, elapsed_time, 0.01)
+    end)
+
+
+    it("should return immediately for a non-positive sleep time", function()
+      local start_time = system.gettime()
+      system.sleep(-1)
+      local end_time = system.gettime()
+      local elapsed_time = end_time - start_time
+      assert.is.near(elapsed_time, 0, 0.01)
+    end)
+
+  end)
+
+end)
diff --git a/spec/02-random_spec.lua b/spec/02-random_spec.lua
new file mode 100644
index 0000000..23b6d95
--- /dev/null
+++ b/spec/02-random_spec.lua
@@ -0,0 +1,47 @@
+local system = require("system")
+
+describe("Random:", function()
+
+  describe("random()", function()
+
+    it("should return random bytes for a valid number of bytes", function()
+        local num_bytes = 1
+        local result, err_msg = system.random(num_bytes)
+        assert.is_nil(err_msg)
+        assert.is.string(result)
+        assert.is_equal(num_bytes, #result)
+    end)
+
+
+    it("should return an empty string for 0 bytes", function()
+        local num_bytes = 0
+        local result, err_msg = system.random(num_bytes)
+        assert.is_nil(err_msg)
+        assert.are.equal("", result)
+    end)
+
+
+    it("should return an error message for an invalid number of bytes", function()
+        local num_bytes = -1
+        local result, err_msg = system.random(num_bytes)
+        assert.is.falsy(result)
+        assert.are.equal("invalid number of bytes, must not be less than 0", err_msg)
+    end)
+
+
+    it("should not return duplicate results", function()
+      local num_bytes = 1025
+      local result1, err_msg = system.random(num_bytes)
+      assert.is_nil(err_msg)
+      assert.is.string(result1)
+
+      local result2, err_msg = system.random(num_bytes)
+      assert.is_nil(err_msg)
+      assert.is.string(result2)
+
+      assert.is_not.equal(result1, result2)
+    end)
+
+  end)
+
+end)
diff --git a/spec/03-environment_spec.lua b/spec/03-environment_spec.lua
new file mode 100644
index 0000000..842ed6f
--- /dev/null
+++ b/spec/03-environment_spec.lua
@@ -0,0 +1,81 @@
+-- Import the library that contains the environment-related functions
+local system = require("system")
+
+describe("Environment Variables:", function()
+
+  describe("setenv()", function()
+
+    it("should set an environment variable", function()
+      assert.is_true(system.setenv("TEST_VAR", "test_value"))
+      assert.is_equal("test_value", system.getenv("TEST_VAR"))
+    end)
+
+
+    local func = system.windows and pending or it --pending on Windows
+    -- Windows will unset a variable if set as an empty string
+    func("should set an empty environment variable value", function()
+      assert.is_true(system.setenv("TEST_VAR", ""))
+      assert.is_equal("", system.getenv("TEST_VAR"))
+    end)
+
+
+    it("should unset an environment variable on nil", function()
+      assert.is_true(system.setenv("TEST_VAR", "test_value"))
+      assert.is_equal("test_value", system.getenv("TEST_VAR"))
+
+      assert.is_true(system.setenv("TEST_VAR", nil))
+      assert.is_nil(system.getenv("TEST_VAR"))
+    end)
+
+
+    it("should error on input bad type", function()
+      assert.has_error(function()
+        system.setenv("TEST_VAR", {})
+      end)
+      assert.has_error(function()
+        system.setenv({}, "test_value")
+      end)
+    end)
+
+
+    it("should return success on deleting a variable that doesn't exist", function()
+      if system.getenv("TEST_VAR") ~= nil then
+        -- clear if it was already set
+        assert.is_true(system.setenv("TEST_VAR", nil))
+      end
+
+      assert.is_true(system.setenv("TEST_VAR", nil)) -- clear again shouldn't fail
+    end)
+
+  end)
+
+
+
+  describe("getenvs()", function()
+
+    it("should list environment variables", function()
+      assert.is_true(system.setenv("TEST_VAR1", nil))
+      assert.is_true(system.setenv("TEST_VAR2", nil))
+      assert.is_true(system.setenv("TEST_VAR3", nil))
+      local envVars1 = system.getenvs()
+      assert.is_true(system.setenv("TEST_VAR1", "test_value1"))
+      assert.is_true(system.setenv("TEST_VAR2", "test_value2"))
+      assert.is_true(system.setenv("TEST_VAR3", "test_value3"))
+      local envVars2 = system.getenvs()
+      assert.is_true(system.setenv("TEST_VAR1", nil))
+      assert.is_true(system.setenv("TEST_VAR2", nil))
+      assert.is_true(system.setenv("TEST_VAR3", nil))
+
+      for k,v in pairs(envVars1) do
+        envVars2[k] = nil
+      end
+      assert.are.same({
+        TEST_VAR1 = "test_value1",
+        TEST_VAR2 = "test_value2",
+        TEST_VAR3 = "test_value3",
+      }, envVars2)
+    end)
+
+  end)
+
+end)
diff --git a/spec/time_spec.lua b/spec/time_spec.lua
deleted file mode 100644
index a017cfe..0000000
--- a/spec/time_spec.lua
+++ /dev/null
@@ -1,31 +0,0 @@
-local system = require 'system.core'
-
-describe('Test time functions', function()
-  it('gettime returns current time', function()
-    local starttime = system.gettime()
-    local expected = os.time()
-    local endtime = system.gettime()
-    local delta = endtime - starttime
-    local avg = starttime + delta/2
-    assert.is_true(expected >= math.floor(starttime))
-    assert.is_true(expected <= math.ceil(endtime))
-    assert.is_near(expected, avg, 1 + delta)
-  end)
-
-  it('monottime returns monotonically increasing time', function()
-    local starttime = system.monotime()
-    local endtime = system.monotime()
-    local delta = endtime - starttime
-    assert.is_true(starttime > 0)
-    assert.is_true(delta >= 0)
-    assert.is_true(system.monotime() - endtime >= 0)
-  end)
-
-  it('sleep will wait for specified amount of time', function()
-    local starttime = system.gettime()
-    local starttick = system.monotime()
-    system.sleep(0.5)
-    assert.is_near(0.5, system.gettime() - starttime, 0.15)
-    assert.is_near(0.5, system.monotime() - starttick, 0.15)
-  end)
-end)