TypeError: object null is not iterable

[manunio]

Describe the bug
While Fuzzing parseDocument threw uncaught exception at

yaml/src/doc/directives.ts

Line 146 in e8576e8

const [, handle, suffix] = source.match(/^(.*!)([^!]*)$/) as string[]

To Reproduce

> const yaml = await import("yaml")
undefined
> const data = '!!�������p: >�: >\n|\x18\x00\x00pro��)�������������������: !!\r: !!: >\n\x07\x04\x00ke'
undefined
> const docs = yaml.parseDocument(data)
Uncaught:
TypeError: object null is not iterable (cannot read property Symbol(Symbol.iterator))
    at Directives.tagName (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/doc/directives.js:121:36)
    at Object.composeScalar (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-scalar.js:13:26)
    at composeNode (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-node.js:24:34)
    at Object.resolveBlockMap (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/resolve-block-map.js:56:15)
    at resolveCollection (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-collection.js:13:27)
    at Object.composeCollection (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-collection.js:47:16)
    at Object.composeNode (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-node.js:31:38)
    at Object.composeDoc (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/compose-doc.js:33:23)
    at Composer.next (/home/maxx/dev/security/oss-fuzz-projects/yaml/dist/compose/composer.js:149:40)
    at next (<anonymous>)

Expected behaviour
parseDocument to not throw exception.

Versions (please complete the following information):

• Environment: Node.js v18.18.2
• yaml: v2.3.3

Additional context
Possible fix for this will be a check against null

diff --git a/src/doc/directives.ts b/src/doc/directives.ts
index add18fc..896c584 100644
--- a/src/doc/directives.ts
+++ b/src/doc/directives.ts
@@ -143,7 +143,12 @@ export class Directives {
       return verbatim
     }

-    const [, handle, suffix] = source.match(/^(.*!)([^!]*)$/) as string[]
+    const matched = source.match(/^(.*!)([^!]*)$/) as string[]
+    if (!matched) {
+      onError(`The ${source} tag is invalid`)
+      return null
+    }
+    const [, handle, suffix] = matched
     if (!suffix) onError(`The ${source} tag has no suffix`)
     const prefix = this.tags[handle]
     if (prefix) {

but i was not able to reproduce this with single error message in doc.errors,

[eemeli]

Ah, that was interesting. Managed to first shorten the input that's required to replicate the issue to just ': | !\r!', and then found the right fix: adding the s dot-all flag to the regexp on the line that's throwing the error, so that its . matches the \r.

[eemeli]

Fix released as 2.3.4.