Add PDF text extraction to MCP read_file and search_files

MCP's read_file previously hard-required UTF-8 text decoding, so any PDF in an allowed folder failed with "Cannot read file as UTF-8 text" — chat attachments already supported PDFs (raw bytes to vision-capable models), but the AI couldn't read one on its own during agentic file-tool use. search_files' content_search had the same gap, silently skipping PDFs. Adds MCPService.extractPDFText(atPath:) using PDFKit (built into macOS, no new dependency) to pull text from a PDF's text layer. Wired into both read_file and search_files' content search. Returns a clear error for scanned/image-only PDFs with no text layer. Automatically covers the Research Agents sub-agent tool loop too, since it shares the same executeTool dispatcher. Verified live: asked the AI to read a real PDF containing "The secret code is PINEAPPLE-42." via read_file — it extracted the text correctly through the MCP tool-call path. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-25 11:44:27 +02:00
parent 377e783a17
commit 69dbf17f5e
2 changed files with 102 additions and 8 deletions
@@ -0,0 +1,68 @@
+//
+//  MCPServicePDFTests.swift
+//  oAITests
+//
+// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0
+// Copyright (C) 2026 Rune Olsen
+
+import Testing
+import Foundation
+import CoreGraphics
+import AppKit
+@testable import oAI
+
+@Suite("MCPService PDF text extraction")
+struct MCPServicePDFTests {
+
+    /// Builds a real, well-formed single-page PDF (via CoreGraphics) containing the given text,
+    /// writes it to a temp file, and returns the path. Using CoreGraphics rather than hand-rolled
+    /// PDF bytes avoids flakiness from malformed xref tables etc.
+    private func makeTestPDF(text: String) throws -> String {
+        let path = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+            .appendingPathExtension("pdf")
+
+        let pdfData = NSMutableData()
+        let consumer = CGDataConsumer(data: pdfData as CFMutableData)!
+        var mediaBox = CGRect(x: 0, y: 0, width: 200, height: 200)
+        let context = CGContext(consumer: consumer, mediaBox: &mediaBox, nil)!
+
+        context.beginPDFPage(nil)
+        let attributedString = NSAttributedString(string: text, attributes: [.font: NSFont.systemFont(ofSize: 24)])
+        let line = CTLineCreateWithAttributedString(attributedString)
+        context.textPosition = CGPoint(x: 10, y: 100)
+        CTLineDraw(line, context)
+        context.endPDFPage()
+        context.closePDF()
+
+        try (pdfData as Data).write(to: path)
+        return path.path
+    }
+
+    @Test("Extracts text from a real PDF's text layer")
+    func extractsTextFromRealPDF() throws {
+        let path = try makeTestPDF(text: "Hello World")
+        defer { try? FileManager.default.removeItem(atPath: path) }
+
+        let extracted = MCPService.shared.extractPDFText(atPath: path)
+        #expect(extracted?.contains("Hello World") == true)
+    }
+
+    @Test("Returns nil for a nonexistent path")
+    func returnsNilForMissingFile() {
+        let extracted = MCPService.shared.extractPDFText(atPath: "/tmp/definitely-does-not-exist-\(UUID().uuidString).pdf")
+        #expect(extracted == nil)
+    }
+
+    @Test("Returns nil for a file that isn't a valid PDF")
+    func returnsNilForGarbageBytes() throws {
+        let path = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+            .appendingPathExtension("pdf")
+        try Data("not a real pdf".utf8).write(to: path)
+        defer { try? FileManager.default.removeItem(at: path) }
+
+        let extracted = MCPService.shared.extractPDFText(atPath: path.path)
+        #expect(extracted == nil)
+    }
+}