fix: AWS Payload Tagging no longer breaks with bad JSONPath (#6358)

Co-authored-by: Ruben Bridgewater <ruben.bridgewater@datadoghq.com>

Author: TophrC-dd

packages/dd-trace/src/config.js

@@ -187,7 +187,7 @@ function validateNamingVersion (versionString) {
  * @param {string | string[]} input
  */
 function splitJSONPathRules (input) {
-  if (!input) return
+  if (!input || input === '$') return
   if (Array.isArray(input)) return input
   if (input === 'all') return []
   return input.split(',')

packages/dd-trace/src/payload-tagging/index.js

@@ -38,7 +38,9 @@ function maybeJSONParseValue (value) {
 function expand (object, expansionRules) {
   for (const rule of expansionRules) {
     jsonpath(rule, object, (value, _type, desc) => {
-      desc.parent[desc.parentProperty] = maybeJSONParseValue(value)
+      if (desc.parent && desc.parentProperty) {
+        desc.parent[desc.parentProperty] = maybeJSONParseValue(value)
+      }
     })
   }
 }
@@ -52,7 +54,9 @@ function expand (object, expansionRules) {
 function redact (object, redactionRules) {
   for (const rule of redactionRules) {
     jsonpath(rule, object, (_value, _type, desc) => {
-      desc.parent[desc.parentProperty] = 'redacted'
+      if (desc.parent && desc.parentProperty) {
+        desc.parent[desc.parentProperty] = 'redacted'
+      }
     })
   }
 }

packages/dd-trace/test/payload-tagging/index.spec.js

@@ -199,6 +199,40 @@ describe('Tagging orchestration', () => {
     assert.strictEqual(tags[`${PAYLOAD_TAG_RESPONSE_PREFIX}.request`], 'foo')
   })
 
+  it('should not fail if the response config contains invalid config', () => {
+    const config = {
+      request: ['invalid,request'],
+      response: ['invalid,$.foo,$.response'],
+      expand: []
+    }
+    const input = {
+      request: 'foo',
+      response: 'bar',
+    }
+    const tags = computeTags(config, input, { maxDepth: 10, prefix: PAYLOAD_TAG_RESPONSE_PREFIX })
+    assert.strictEqual(tags[`${PAYLOAD_TAG_RESPONSE_PREFIX}.response`], 'redacted')
+    assert.strictEqual(tags[`${PAYLOAD_TAG_RESPONSE_PREFIX}.request`], 'foo')
+  })
+
+  it('should apply expansion rules with dollar identical to an empty input', () => {
+    const config = {
+      request: ['$'],
+      response: ['$'],
+      expand: ['$.request', '$.response', '$.invalid'],
+    }
+    const input = {
+      request: '{ "foo": "bar" }',
+      response: '{ "baz": "quux" }',
+      invalid: '{ invalid JSON }',
+      untargeted: '{ "foo": "bar" }',
+    }
+    const tags = computeTags(config, input, { maxDepth: 10, prefix: 'foo' })
+    assert.strictEqual(tags['foo.request.foo'], 'bar')
+    assert.strictEqual(tags['foo.response.baz'], 'quux')
+    assert.strictEqual(tags['foo.invalid'], '{ invalid JSON }')
+    assert.strictEqual(tags['foo.untargeted'], '{ "foo": "bar" }')
+  })
+
   it('should apply expansion rules', () => {
     const config = {
       request: [],