[junyu33]

Problem

The default YAML workspace resolver treats absolute schema URIs as relative paths and passes them to Utils.resolvePath().

When combining multiple schemas, this can turn a valid URI such as file:///c:/schemas/frontmatter.json into:

schemaservice://combinedschema/file%3A/c%3A/schemas/frontmatter.json

The resulting URI cannot be loaded, producing an “Unable to load schema … No content” diagnostic.

This was reproduced in the Slidev VS Code extension on Windows.

Fix

Return references with an explicit URI scheme unchanged. Relative references continue through the existing resolution logic, including embedded-document handling.

Tests

Add 19 regression cases covering:

• Absolute file, HTTP(S), and custom-scheme URIs.
• Relative paths, parent paths, spaces, and embedded documents.
• Successful validation with combined schemas.
• Retained diagnostics for invalid values and missing schemas.

Verified locally on Windows:

• pnpm test — all 20 tests pass.
• pnpm run build
• pnpm run lint
• Formatting checks for the changed files.