Add basic custom resolution features

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

README.markdown

@@ -58,6 +58,7 @@ without passing a command will print convenient reference documentation:
 The following global options apply to all commands:
 
 - `--verbose / -v`: Enable verbose output
+- `--resolve / -r`: Import the given JSON Schema into the resolution context
 
 Coming Soon
 -----------

docs/bundle.markdown

@@ -15,10 +15,8 @@ The JSON Schema CLI supports this functionality through the `bundle` command.
 Examples
 --------
 
-<!-- TODO: Actually exemplify real remote bundling -->
-
-### Bundle a JSON Schema
+### Bundle a JSON Schema preloading another one
 
 ```sh
-jsonschema bundle path/to/my/schema.json
+jsonschema bundle path/to/my/schema.json --resolve path/to/external.json
 ```

src/command_bundle.cc

@@ -10,7 +10,7 @@
 auto intelligence::jsonschema::cli::bundle(
     const std::span<const std::string> &arguments) -> int {
   const auto options{parse_options(arguments, {})};
-  CLI_ENSURE(!options.at("").empty(), "You must pass a JSON Schema as input")
+  CLI_ENSURE(!options.at("").empty(), "You must pass a JSON Schema as input");
   auto schema{sourcemeta::jsontoolkit::from_file(options.at("").front())};
   sourcemeta::jsontoolkit::bundle(
       schema, sourcemeta::jsontoolkit::default_schema_walker, resolver(options))

src/main.cc

@@ -14,6 +14,7 @@ constexpr std::string_view USAGE_DETAILS{R"EOF(
 Global Options:
 
    --verbose, -v    Enable verbose output
+   --resolve, -r    Import the given JSON Schema into the resolution context
 
 Commands:
 

src/utils.cc

@@ -1,10 +1,11 @@
 #include "utils.h"
 
-#include <cassert>  // assert
-#include <fstream>  // std::ofstream
-#include <iostream> // std::cerr
-#include <optional> // std::optional, std::nullopt
-#include <sstream>  // std::ostringstream
+#include <cassert>   // assert
+#include <fstream>   // std::ofstream
+#include <iostream>  // std::cerr
+#include <optional>  // std::optional, std::nullopt
+#include <sstream>   // std::ostringstream
+#include <stdexcept> // std::runtime_error
 
 namespace {
 
@@ -116,10 +117,43 @@ auto pretty_evaluate_callback(
   std::cerr << "\")\n";
 }
 
-// TODO: Use input options to get a custom-made resolver
-auto resolver(const std::map<std::string, std::vector<std::string>> &)
+auto resolver(const std::map<std::string, std::vector<std::string>> &options)
     -> sourcemeta::jsontoolkit::SchemaResolver {
-  return sourcemeta::jsontoolkit::official_resolver;
+  if (!options.contains("resolve") && !options.contains("r")) {
+    return sourcemeta::jsontoolkit::official_resolver;
+  }
+
+  std::map<std::string, sourcemeta::jsontoolkit::JSON> schemas;
+  const std::string option{options.contains("resolve") ? "resolve" : "r"};
+  for (const auto &schema_path : options.at(option)) {
+    const auto schema{sourcemeta::jsontoolkit::from_file(schema_path)};
+    // TODO: Use the current resolver as its building up
+    const auto id{sourcemeta::jsontoolkit::id(
+                      schema, sourcemeta::jsontoolkit::official_resolver)
+                      .get()};
+    if (!id.has_value()) {
+      std::ostringstream error;
+      error << "Cannot determine the identifier of the schema: " << schema_path;
+      throw std::runtime_error(error.str());
+    }
+
+    // TODO: Throw if we are overriding with a duplicate id
+    // TODO: We need to frame to add subschemas too?
+    schemas.insert({id.value(), schema});
+    log_verbose(options) << "Loading schema: " << schema_path << "\n";
+  }
+
+  return [schemas](std::string_view identifier)
+             -> std::future<std::optional<sourcemeta::jsontoolkit::JSON>> {
+    const std::string string_identifier{identifier};
+    if (schemas.contains(string_identifier)) {
+      std::promise<std::optional<sourcemeta::jsontoolkit::JSON>> promise;
+      promise.set_value(schemas.at(string_identifier));
+      return promise.get_future();
+    }
+
+    return sourcemeta::jsontoolkit::official_resolver(identifier);
+  };
 }
 
 auto log_verbose(const std::map<std::string, std::vector<std::string>> &options)

test/CMakeLists.txt

@@ -15,5 +15,6 @@ add_jsonschema_test_unix(frame)
 add_jsonschema_test_unix(validate_pass)
 add_jsonschema_test_unix(validate_fail)
 add_jsonschema_test_unix(bundle_non_remote)
+add_jsonschema_test_unix(bundle_remote_single_schema)
 add_jsonschema_test_unix(test_single_pass)
 add_jsonschema_test_unix(test_single_fail)

test/bundle_remote_single_schema.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/schema.json"
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://example.com",
+  "$ref": "nested"
+}
+EOF
+
+cat << 'EOF' > "$TMP/remote.json"
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://example.com/nested",
+  "type": "string"
+}
+EOF
+
+"$1" bundle "$TMP/schema.json" --resolve "$TMP/remote.json" > "$TMP/result.json"
+
+cat << 'EOF' > "$TMP/expected.json"
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://example.com",
+  "$ref": "nested",
+  "$defs": {
+    "https://example.com/nested": {
+      "$schema": "https://json-schema.org/draft/2020-12/schema",
+      "$id": "https://example.com/nested",
+      "type": "string"
+    }
+  }
+}
+EOF
+
+diff "$TMP/result.json" "$TMP/expected.json"