Add unit tests for the Chrome OS printing context.

Add unit tests for SettingsToCupsOptions() in
printing_context_chromeos.cc.

Also refactor the code a bit to expose this function for testing.

Bug: 1001398
Test: ./printing_unittests

Cq-Depend: 2390967
Change-Id: Id0c0765e5ce6a3f3cde3d294afce33c9720f215a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2389102
Commit-Queue: Pranav Batra <[email protected]>
Reviewed-by: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#805084}
diff --git a/printing/printing_context_chromeos_unittest.cc b/printing/printing_context_chromeos_unittest.cc
new file mode 100644
index 0000000..90086b81
--- /dev/null
+++ b/printing/printing_context_chromeos_unittest.cc
@@ -0,0 +1,99 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "printing/printing_context_chromeos.h"
+
+#include <string.h>
+
+#include "printing/backend/cups_ipp_constants.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace printing {
+
+namespace {
+
+const char* GetOptionValue(const std::vector<ScopedCupsOption>& options,
+                           const char* option_name) {
+  DCHECK(option_name);
+  const char* ret = nullptr;
+  for (const auto& option : options) {
+    EXPECT_TRUE(option->name);
+    EXPECT_TRUE(option->value);
+    if (option->name && !strcmp(option_name, option->name)) {
+      EXPECT_EQ(nullptr, ret)
+          << "Multiple options with name " << option_name << " found.";
+      ret = option->value;
+    }
+  }
+  return ret;
+}
+
+class TestPrintSettings : public PrintSettings {
+ public:
+  TestPrintSettings() { set_duplex_mode(mojom::DuplexMode::kSimplex); }
+};
+
+class PrintingContextTest : public testing::Test {
+ public:
+  const char* Get(const char* name) const {
+    return GetOptionValue(SettingsToCupsOptions(settings_), name);
+  }
+  TestPrintSettings settings_;
+};
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Color) {
+  settings_.set_color(mojom::ColorModel::kGray);
+  EXPECT_STREQ("monochrome", Get(kIppColor));
+  settings_.set_color(mojom::ColorModel::kColor);
+  EXPECT_STREQ("color", Get(kIppColor));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Duplex) {
+  settings_.set_duplex_mode(mojom::DuplexMode::kSimplex);
+  EXPECT_STREQ("one-sided", Get(kIppDuplex));
+  settings_.set_duplex_mode(mojom::DuplexMode::kLongEdge);
+  EXPECT_STREQ("two-sided-long-edge", Get(kIppDuplex));
+  settings_.set_duplex_mode(mojom::DuplexMode::kShortEdge);
+  EXPECT_STREQ("two-sided-short-edge", Get(kIppDuplex));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Media) {
+  EXPECT_STREQ("", Get(kIppMedia));
+  settings_.set_requested_media(
+      {gfx::Size(297000, 420000), "iso_a3_297x420mm"});
+  EXPECT_STREQ("iso_a3_297x420mm", Get(kIppMedia));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Copies) {
+  settings_.set_copies(3);
+  EXPECT_STREQ("3", Get(kIppCopies));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Collate) {
+  EXPECT_STREQ("separate-documents-uncollated-copies", Get(kIppCollate));
+  settings_.set_collate(true);
+  EXPECT_STREQ("separate-documents-collated-copies", Get(kIppCollate));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Pin) {
+  EXPECT_STREQ(nullptr, Get(kIppPin));
+  settings_.set_pin_value("1234");
+  EXPECT_STREQ("1234", Get(kIppPin));
+}
+
+TEST_F(PrintingContextTest, SettingsToCupsOptions_Resolution) {
+  EXPECT_STREQ(nullptr, Get(kIppResolution));
+  settings_.set_dpi_xy(0, 300);
+  EXPECT_STREQ(nullptr, Get(kIppResolution));
+  settings_.set_dpi_xy(300, 0);
+  EXPECT_STREQ(nullptr, Get(kIppResolution));
+  settings_.set_dpi(600);
+  EXPECT_STREQ("600dpi", Get(kIppResolution));
+  settings_.set_dpi_xy(600, 1200);
+  EXPECT_STREQ("600x1200dpi", Get(kIppResolution));
+}
+
+}  // namespace
+
+}  // namespace printing