[clang-tools-extra] [llvm] [llvm] add support for mustache templating language (PR #105893)

[Paul Kirth via cfe-commits]

================
@@ -0,0 +1,135 @@
+//===- llvm/unittest/Support/MustacheTest.cpp ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Test conforming to Mustache 1.4.2 spec found here:
+// https://github.com/mustache/spec
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Mustache.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace llvm::mustache;
+using namespace llvm::json;
+
+TEST(MustacheInterpolation, NoInterpolation) {
+  // Mustache-free templates should render as-is.
+  Value D = {};
+  auto T = Template::createTemplate("Hello from {Mustache}!\n");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("Hello from {Mustache}!\n", Out);
+}
+
+TEST(MustacheInterpolation, BasicInterpolation) {
+  // Unadorned tags should interpolate content into the template.
+  Value D = Object{{"subject", "World"}};
+  auto T = Template::createTemplate("Hello, {{subject}}!");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("Hello, World!", Out);
+}
+
+TEST(MustacheInterpolation, NoReinterpolation) {
+  // Interpolated tag output should not be re-interpolated.
+  Value D = Object{{"template", "{{planet}}"}, {"planet", "Earth"}};
+  auto T = Template::createTemplate("{{template}}: {{planet}}");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("{{planet}}: Earth", Out);
+}
+
+TEST(MustacheInterpolation, HTMLEscaping) {
+  // Interpolated tag output should not be re-interpolated.
+  Value D = Object{
+      {"forbidden", "& \" < >"},
+  };
+  auto T = Template::createTemplate(
+      "These characters should be HTML escaped: {{forbidden}}\n");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("These characters should be HTML escaped: & " < >\n",
+            Out);
+}
+
+TEST(MustacheInterpolation, Ampersand) {
+  // Interpolated tag output should not be re-interpolated.
+  Value D = Object{
+      {"forbidden", "& \" < >"},
+  };
+  auto T = Template::createTemplate(
+      "These characters should not be HTML escaped: {{&forbidden}}\n");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("These characters should not be HTML escaped: & \" < >\n", Out);
+}
+
+TEST(MustacheInterpolation, BasicIntegerInterpolation) {
+  Value D = Object{{"mph", 85}};
+  auto T = Template::createTemplate("{{mph}} miles an hour!");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("85 miles an hour!", Out);
+}
+
+TEST(MustacheInterpolation, BasicDecimalInterpolation) {
+  Value D = Object{{"power", 1.21}};
+  auto T = Template::createTemplate("{{power}} jiggawatts!");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("1.21 jiggawatts!", Out);
+}
+
+TEST(MustacheInterpolation, BasicNullInterpolation) {
+  Value D = Object{{"cannot", nullptr}};
+  auto T = Template::createTemplate("I ({{cannot}}) be seen!");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("I () be seen!", Out);
+}
+
+TEST(MustacheInterpolation, BasicContextMissInterpolation) {
+  Value D = Object{};
+  auto T = Template::createTemplate("I ({{cannot}}) be seen!");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("I () be seen!", Out);
+}
+
+TEST(MustacheInterpolation, DottedNamesBasicInterpolation) {
+  Value D = Object{{"person", Object{{"name", "Joe"}}}};
+  auto T = Template::createTemplate(
+      "{{person.name}} == {{#person}}{{name}}{{/person}}");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("Joe == Joe", Out);
+}
+
+TEST(MustacheInterpolation, DottedNamesArbitraryDepth) {
+  Value D = Object{
+      {"a",
+       Object{{"b",
+               Object{{"c",
+                       Object{{"d",
+                               Object{{"e", Object{{"name", "Phil"}}}}}}}}}}}};
+  auto T = Template::createTemplate("{{a.b.c.d.e.name}} == Phil");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("Phil == Phil", Out);
+}
+
+TEST(MustacheInterpolation, ImplicitIteratorsBasicInterpolation) {
+  Value D = "world";
+  auto T = Template::createTemplate("Hello, {{.}}!\n");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("Hello, world!\n", Out);
+}
+
+TEST(MustacheInterpolation, InterpolationSurroundingWhitespace) {
+  Value D = Object{{"string", "---"}};
+  auto T = Template::createTemplate("| {{string}} |");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("| --- |", Out);
+}
+
+TEST(MustacheInterpolation, InterpolationWithPadding) {
+  Value D = Object{{"string", "---"}};
+  auto T = Template::createTemplate("|{{ string }}|");
+  auto Out = T.get().render(D);
+  EXPECT_EQ("|---|", Out);
+}
----------------
ilovepi wrote:

Probably also test some text w/ newlines, and other special characters? Perhaps parameterizing some of the tests would be useful (e.g. test all whitespace by substituting in difference whitespace characters. IIRC the JSON tests have some of these.

https://github.com/llvm/llvm-project/pull/105893