diff --git a/json-schema/schema.json b/json-schema/schema.json
index d701230..03fe0b1 100644
--- a/json-schema/schema.json
+++ b/json-schema/schema.json
@@ -17,14 +17,7 @@
           "const": "Feature"
         },
         "properties": {
-          "allOf": [
-            {
-              "$ref": "#/definitions/require_any_field"
-            },
-            {
-              "$ref": "#/definitions/fields"
-            }
-          ]
+          "$ref": "#/definitions/fields"
         },
         "assets": {
           "$comment": "This validates the fields in Item Assets, but does not require them.",
@@ -75,9 +68,7 @@
       "allOf": [
         {
           "$ref": "#/definitions/stac_extensions"
-        }
-      ],
-      "anyOf": [
+        },
         {
           "$comment": "Requires at least one provider to contain processing fields.",
           "type": "object",
@@ -108,7 +99,7 @@
                     }
                   },
                   {
-                    "$ref": "#/definitions/require_any_field"
+                    "$ref": "#/definitions/fields"
                   }
                 ]
               }
@@ -118,18 +109,11 @@
         {
           "$comment": "Requires at least one asset to contain processing fields.",
           "type": "object",
-          "required": [
-            "assets"
-          ],
           "properties": {
             "assets": {
               "type": "object",
-              "not": {
-                "additionalProperties": {
-                  "not": {
-                    "$ref": "#/definitions/require_any_field"
-                  }
-                }
+              "additionalProperties": {
+                "$ref": "#/definitions/fields"
               }
             }
           }
@@ -137,18 +121,11 @@
         {
           "$comment": "Requires at least one item asset definition to contain processing fields.",
           "type": "object",
-          "required": [
-            "item_assets"
-          ],
           "properties": {
             "item_assets": {
               "type": "object",
-              "not": {
-                "additionalProperties": {
-                  "not": {
-                    "$ref": "#/definitions/require_any_field"
-                  }
-                }
+              "additionalProperties": {
+                "$ref": "#/definitions/fields"
               }
             }
           }
@@ -156,12 +133,46 @@
         {
           "type": "object",
           "$comment": "Requires at least one summary to be a processing field.",
-          "required": [
-            "summaries"
-          ],
           "properties": {
             "summaries": {
-              "$ref": "#/definitions/require_any_field"
+              "type": "object",
+              "properties": {
+                "processing:expression": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/definitions/fields/properties/processing:expression"
+                  },
+                  "minItems": 1
+                },
+                "processing:facility": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/definitions/fields/properties/processing:facility"
+                  },
+                  "minItems": 1
+                },
+                "processing:level": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/definitions/fields/properties/processing:level"
+                  },
+                  "minItems": 1
+                },
+                "processing:lineage": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/definitions/fields/properties/processing:lineage"
+                  },
+                  "minItems": 1
+                },
+                "processing:software": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/definitions/fields/properties/processing:software"
+                  },
+                  "minItems": 1
+                }
+              }
             }
           }
         }
@@ -200,15 +211,6 @@
         }
       }
     },
-    "require_any_field": {
-      "anyOf": [
-        {"type": "object", "required": ["processing:expression"]},
-        {"type": "object", "required": ["processing:lineage"]},
-        {"type": "object", "required": ["processing:level"]},
-        {"type": "object", "required": ["processing:facility"]},
-        {"type": "object", "required": ["processing:software"]}
-      ]
-    },
     "fields": {
       "type": "object",
       "properties": {
diff --git a/package.json b/package.json
index df44906..16e7cb8 100644
--- a/package.json
+++ b/package.json
@@ -2,12 +2,15 @@
   "name": "stac-extensions",
   "version": "1.1.0",
   "scripts": {
-    "test": "npm run check-markdown && npm run check-examples",
+    "test": "jest && npm run check-markdown && npm run check-examples",
     "check-markdown": "remark . -f -r .github/remark.yaml",
     "check-examples": "stac-node-validator . --lint --verbose --schemaMap https://stac-extensions.github.io/processing/v1.1.0/schema.json=./json-schema/schema.json",
     "format-examples": "stac-node-validator . --format --schemaMap https://stac-extensions.github.io/processing/v1.1.0/schema.json=./json-schema/schema.json"
   },
+  "type": "module",
   "dependencies": {
+    "ajv": "^8.8.2",
+    "jest": "^27.4.5",
     "remark-cli": "^8.0.0",
     "remark-lint": "^7.0.0",
     "remark-lint-no-html": "^2.0.0",
diff --git a/tests/collection.test.js b/tests/collection.test.js
new file mode 100644
index 0000000..9efb2ed
--- /dev/null
+++ b/tests/collection.test.js
@@ -0,0 +1,179 @@
+const {join} = require('path');
+const {promises} = require('fs');
+const {AjvOptions, rootDirectory, schemaPath} = require('./validation.js');
+const ajv = new (require('ajv'))(AjvOptions);
+
+const examplePath = join(rootDirectory, 'examples/collection.json');
+
+let validate;
+beforeAll(async () => {
+	const data = JSON.parse(await promises.readFile(schemaPath));
+	validate = await ajv.compileAsync(data);
+});
+
+let example;
+beforeEach(async () => {
+	example = JSON.parse(await promises.readFile(examplePath));
+});
+
+describe('Collection example', () => {
+	it('should pass validation', async () => {
+		let valid = validate(example);
+
+		expect(valid).toBeTruthy();
+	});
+
+	it('should fail validation when providers processing expression is invalid', async () => {
+		// given
+		example.providers[0]['processing:expression'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/providers/0/processing:expression'
+					&& error.message === 'must be object',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when asset processing expression is invalid', async () => {
+		// given
+		example.assets = {
+			'example': {
+				'href': 'https://example.org/file.xyz',
+				'processing:expression': null,
+			}
+		};
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/assets/example/processing:expression'
+					&& error.message === 'must be object',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when item asset processing expression is invalid', async () => {
+		// given
+		example.item_assets = {
+			'example': {
+				'href': 'https://example.org/file.xyz',
+				'processing:expression': null,
+			}
+		};
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/item_assets/example/processing:expression'
+					&& error.message === 'must be object',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when summary processing expression is invalid', async () => {
+		// given
+		example.summaries['processing:expression'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/summaries/processing:expression'
+					&& error.message === 'must be array',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when summary processing facility is invalid', async () => {
+		// given
+		example.summaries['processing:facility'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/summaries/processing:facility'
+					&& error.message === 'must be array',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when summary processing level is invalid', async () => {
+		// given
+		example.summaries['processing:level'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/summaries/processing:level'
+					&& error.message === 'must be array',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when summary processing lineage is invalid', async () => {
+		// given
+		example.summaries['processing:lineage'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/summaries/processing:lineage'
+					&& error.message === 'must be array',
+			)
+		).toBeTruthy();
+	});
+
+	it('should fail validation when summary processing software is invalid', async () => {
+		// given
+		example.summaries['processing:software'] = null;
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/summaries/processing:software'
+					&& error.message === 'must be array',
+			)
+		).toBeTruthy();
+	});
+});
diff --git a/tests/item.test.js b/tests/item.test.js
new file mode 100644
index 0000000..1cc0a94
--- /dev/null
+++ b/tests/item.test.js
@@ -0,0 +1,43 @@
+const {join} = require('path');
+const {promises} = require('fs');
+const {AjvOptions, rootDirectory, schemaPath} = require('./validation.js');
+const ajv = new (require('ajv'))(AjvOptions);
+
+const examplePath = join(rootDirectory, 'examples/item.json');
+
+let validate;
+beforeAll(async () => {
+	const data = JSON.parse(await promises.readFile(schemaPath));
+	validate = await ajv.compileAsync(data);
+});
+
+let example;
+beforeEach(async () => {
+	example = JSON.parse(await promises.readFile(examplePath));
+});
+
+describe('Item example', () => {
+	it('should pass validation', async () => {
+		let valid = validate(example);
+
+		expect(valid).toBeTruthy();
+	});
+
+	it('should fail validation when processing expression is invalid', async () => {
+		// given
+		example.properties = {'processing:expression': null};
+
+		// when
+		let valid = validate(example);
+
+		// then
+		expect(valid).toBeFalsy();
+		expect(
+			validate.errors.some(
+				(error) =>
+					error.instancePath === '/properties/processing:expression'
+					&& error.message === 'must be object',
+			)
+		).toBeTruthy();
+	});
+});
diff --git a/tests/validation.js b/tests/validation.js
new file mode 100644
index 0000000..bfe02cf
--- /dev/null
+++ b/tests/validation.js
@@ -0,0 +1,29 @@
+const axios = require('axios');
+const { dirname, join } = require('path');
+const iriFormats = require('stac-node-validator/iri.js');
+
+const Schemas = new Map();
+const loadSchema = function (uri) {
+	let existing = Schemas.get(uri);
+	if (existing == null) {
+		existing = loadSchemaFromUri(uri);
+		Schemas.set(uri, existing);
+	}
+	return existing;
+}
+
+/**
+ * function passed in to Ajv instance which allows us to load schemas from a url at run time.
+ */
+module.exports.loadSchemaFromUri = async function (uri) {
+	try {
+		let response = await axios.get(uri);
+		return response.data;
+	} catch (error) {
+		throw new Error(`-- Schema at '${uri}' not found. Please ensure all entries in 'stac_extensions' are valid.`);
+	}
+}
+
+module.exports.AjvOptions = {loadSchema, formats: Object.assign(iriFormats)};
+module.exports.rootDirectory = dirname(__dirname);
+module.exports.schemaPath = join(module.exports.rootDirectory, 'json-schema/schema.json');