jsonschema: resolve remote references

Support remote references.
Most of the machinery was in place; we just had to define the
right loader, copy files from the test repo, and download
the meta-schema files from json-schema.org.

Change-Id: Ib588200ef0fa483641b9b53f9904f53b39dc4b82
Reviewed-on: https://go-review.googlesource.com/c/tools/+/670795
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

jsonschema/testdata/remotes/README.md

@@ -0,0 +1,4 @@
+# JSON Schema test suite: remote references
+
+These files were copied from
+https://github.com/json-schema-org/JSON-Schema-Test-Suite/tree/83e866b46c9f9e7082fd51e83a61c5f2145a1ab7/remotes.

jsonschema/testdata/remotes/different-id-ref-string.json

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+{
+    "$id": "http://localhost:1234/real-id-ref-string.json",
+    "$defs": {"bar": {"type": "string"}},
+    "$ref": "#/$defs/bar"
+}

jsonschema/testdata/remotes/draft2020-12/baseUriChange/folderInteger.json

@@ -0,0 +1,4 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "integer"
+}

jsonschema/testdata/remotes/draft2020-12/baseUriChangeFolder/folderInteger.json

@@ -0,0 +1,4 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "integer"
+}

jsonschema/testdata/remotes/draft2020-12/baseUriChangeFolderInSubschema/folderInteger.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "integer"
+}

jsonschema/testdata/remotes/draft2020-12/detached-dynamicref.json

@@ -0,0 +1,13 @@
+{
+  "$id": "http://localhost:1234/draft2020-12/detached-dynamicref.json",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$defs": {
+    "foo": {
+      "$dynamicRef": "#detached"
+    },
+    "detached": {
+      "$dynamicAnchor": "detached",
+      "type": "integer"
+    }
+  }
+}

jsonschema/testdata/remotes/draft2020-12/detached-ref.json

@@ -0,0 +1,13 @@
+{
+  "$id": "http://localhost:1234/draft2020-12/detached-ref.json",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$defs": {
+    "foo": {
+      "$ref": "#detached"
+    },
+    "detached": {
+      "$anchor": "detached",
+      "type": "integer"
+    }
+  }
+}

jsonschema/testdata/remotes/draft2020-12/extendible-dynamic-ref.json

@@ -0,0 +1,21 @@
+{
+    "description": "extendible array",
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "http://localhost:1234/draft2020-12/extendible-dynamic-ref.json",
+    "type": "object",
+    "properties": {
+        "elements": {
+            "type": "array",
+            "items": {
+                "$dynamicRef": "#elements"
+            }
+        }
+    },
+    "required": ["elements"],
+    "additionalProperties": false,
+    "$defs": {
+        "elements": {
+            "$dynamicAnchor": "elements"
+        }
+    }
+}

jsonschema/testdata/remotes/draft2020-12/format-assertion-false.json

@@ -0,0 +1,13 @@
+{
+    "$id": "http://localhost:1234/draft2020-12/format-assertion-false.json",
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/core": true,
+        "https://json-schema.org/draft/2020-12/vocab/format-assertion": false
+    },
+    "$dynamicAnchor": "meta",
+    "allOf": [
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/core" },
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/format-assertion" }
+    ]
+}

jsonschema/testdata/remotes/draft2020-12/format-assertion-true.json

@@ -0,0 +1,13 @@
+{
+    "$id": "http://localhost:1234/draft2020-12/format-assertion-true.json",
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/core": true,
+        "https://json-schema.org/draft/2020-12/vocab/format-assertion": true
+    },
+    "$dynamicAnchor": "meta",
+    "allOf": [
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/core" },
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/format-assertion" }
+    ]
+}

jsonschema/testdata/remotes/draft2020-12/integer.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "integer"
+}

jsonschema/testdata/remotes/draft2020-12/locationIndependentIdentifier.json

@@ -0,0 +1,12 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$defs": {
+        "refToInteger": {
+            "$ref": "#foo"
+        },
+        "A": {
+            "$anchor": "foo",
+            "type": "integer"
+        }
+    }
+}

jsonschema/testdata/remotes/draft2020-12/metaschema-no-validation.json

@@ -0,0 +1,13 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "http://localhost:1234/draft2020-12/metaschema-no-validation.json",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/applicator": true,
+        "https://json-schema.org/draft/2020-12/vocab/core": true
+    },
+    "$dynamicAnchor": "meta",
+    "allOf": [
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/applicator" },
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/core" }
+    ]
+}

jsonschema/testdata/remotes/draft2020-12/metaschema-optional-vocabulary.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "http://localhost:1234/draft2020-12/metaschema-optional-vocabulary.json",
+    "$vocabulary": {
+        "https://json-schema.org/draft/2020-12/vocab/validation": true,
+        "https://json-schema.org/draft/2020-12/vocab/core": true,
+        "http://localhost:1234/draft/2020-12/vocab/custom": false
+    },
+    "$dynamicAnchor": "meta",
+    "allOf": [
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/validation" },
+        { "$ref": "https://json-schema.org/draft/2020-12/meta/core" }
+    ]
+}

jsonschema/testdata/remotes/draft2020-12/name-defs.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$defs": {
+        "orNull": {
+            "anyOf": [
+                {
+                    "type": "null"
+                },
+                {
+                    "$ref": "#"
+                }
+            ]
+        }
+    },
+    "type": "string"
+}

jsonschema/testdata/remotes/draft2020-12/nested/foo-ref-string.json

@@ -0,0 +1,7 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "object",
+    "properties": {
+        "foo": {"$ref": "string.json"}
+    }
+}

jsonschema/testdata/remotes/draft2020-12/nested/string.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "string"
+}

jsonschema/testdata/remotes/draft2020-12/prefixItems.json

@@ -0,0 +1,7 @@
+{
+    "$id": "http://localhost:1234/draft2020-12/prefixItems.json",
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "prefixItems": [
+        {"type": "string"}
+    ]
+}

jsonschema/testdata/remotes/draft2020-12/ref-and-defs.json

@@ -0,0 +1,12 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "http://localhost:1234/draft2020-12/ref-and-defs.json",
+    "$defs": {
+        "inner": {
+            "properties": {
+                "bar": { "type": "string" }
+            }
+        }
+    },
+    "$ref": "#/$defs/inner"
+}

jsonschema/testdata/remotes/draft2020-12/subSchemas.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$defs": {
+        "integer": {
+            "type": "integer"
+        },
+        "refToInteger": {
+            "$ref": "#/$defs/integer"
+        }
+    }
+}