fix(filters): handle sync-flush terminated zlib streams in FlateDecode (#20)

* fix(filters): handle sync-flush terminated zlib streams in FlateDecode

pako.inflate() returns undefined (rather than throwing) for zlib streams
terminated with a sync-flush marker (00 00 FF FF) instead of a proper
final block. Some PDF generators like PDFium produce these streams.

The undefined result propagated through FilterPipeline and caused a
TypeError in downstream code trying to access .length on undefined
chunks.

FlateFilter.decode() now detects this case and recovers the
decompressed data from pako's internal output buffer. Truly corrupt
streams return empty rather than throwing, consistent with the
library's lenient approach to malformed PDFs.

Closes #16

* chore: gitignore fixtures/private/

* chore: change testing timestamp authority

* chore: formatting

Author: Mythie

.gitignore

@@ -50,6 +50,7 @@ debug/
 
 # Benchmark fixtures (downloaded at runtime)
 fixtures/benchmarks/
+fixtures/private/
 
 # Temporary files
 tmp/

content/docs/advanced/low-level-drawing.mdx

@@ -25,9 +25,8 @@ page.drawOperators([
 ```
 
 <Callout type="warn">
-  The low-level API requires understanding of PDF content stream structure.
-  Invalid operator sequences may produce corrupted PDFs. Use the high-level
-  methods when they're sufficient.
+  The low-level API requires understanding of PDF content stream structure. Invalid operator
+  sequences may produce corrupted PDFs. Use the high-level methods when they're sufficient.
 </Callout>
 
 ---
@@ -36,15 +35,15 @@ page.drawOperators([
 
 The high-level methods (`drawRectangle`, `drawText`, etc.) cover most needs. Reach for the low-level API when you need:
 
-| Feature | Low-Level Approach |
-| --- | --- |
-| Matrix transforms | `ops.concatMatrix()` for arbitrary rotation/scale/skew |
-| Gradients | `createAxialShading()` or `createRadialShading()` |
-| Repeating patterns | `createTilingPattern()` or `createImagePattern()` |
-| Blend modes | `createExtGState({ blendMode: "Multiply" })` |
-| Clipping regions | `ops.clip()` with `ops.endPath()` |
-| Reusable graphics | `createFormXObject()` for stamps/watermarks |
-| Fine-grained control | Direct operator sequences |
+| Feature              | Low-Level Approach                                     |
+| -------------------- | ------------------------------------------------------ |
+| Matrix transforms    | `ops.concatMatrix()` for arbitrary rotation/scale/skew |
+| Gradients            | `createAxialShading()` or `createRadialShading()`      |
+| Repeating patterns   | `createTilingPattern()` or `createImagePattern()`      |
+| Blend modes          | `createExtGState({ blendMode: "Multiply" })`           |
+| Clipping regions     | `ops.clip()` with `ops.endPath()`                      |
+| Reusable graphics    | `createFormXObject()` for stamps/watermarks            |
+| Fine-grained control | Direct operator sequences                              |
 
 ---
 
@@ -59,80 +58,80 @@ import { ops } from "@libpdf/core";
 ### Graphics State
 
 ```typescript
-ops.pushGraphicsState()     // Save current state (q)
-ops.popGraphicsState()      // Restore saved state (Q)
-ops.setGraphicsState(name)  // Apply ExtGState resource (gs)
-ops.concatMatrix(a, b, c, d, e, f)  // Transform CTM (cm)
+ops.pushGraphicsState(); // Save current state (q)
+ops.popGraphicsState(); // Restore saved state (Q)
+ops.setGraphicsState(name); // Apply ExtGState resource (gs)
+ops.concatMatrix(a, b, c, d, e, f); // Transform CTM (cm)
 ```
 
 ### Path Construction
 
 ```typescript
-ops.moveTo(x, y)            // Begin subpath (m)
-ops.lineTo(x, y)            // Line to point (l)
-ops.curveTo(x1, y1, x2, y2, x3, y3)  // Cubic bezier (c)
-ops.rectangle(x, y, w, h)   // Rectangle shorthand (re)
-ops.closePath()             // Close subpath (h)
+ops.moveTo(x, y); // Begin subpath (m)
+ops.lineTo(x, y); // Line to point (l)
+ops.curveTo(x1, y1, x2, y2, x3, y3); // Cubic bezier (c)
+ops.rectangle(x, y, w, h); // Rectangle shorthand (re)
+ops.closePath(); // Close subpath (h)
 ```
 
 ### Path Painting
 
 ```typescript
-ops.stroke()                // Stroke path (S)
-ops.fill()                  // Fill path, non-zero winding (f)
-ops.fillEvenOdd()           // Fill path, even-odd rule (f*)
-ops.fillAndStroke()         // Fill then stroke (B)
-ops.endPath()               // Discard path without painting (n)
+ops.stroke(); // Stroke path (S)
+ops.fill(); // Fill path, non-zero winding (f)
+ops.fillEvenOdd(); // Fill path, even-odd rule (f*)
+ops.fillAndStroke(); // Fill then stroke (B)
+ops.endPath(); // Discard path without painting (n)
 ```
 
 ### Clipping
 
 ```typescript
-ops.clip()                  // Set clip region, non-zero (W)
-ops.clipEvenOdd()           // Set clip region, even-odd (W*)
+ops.clip(); // Set clip region, non-zero (W)
+ops.clipEvenOdd(); // Set clip region, even-odd (W*)
 ```
 
 ### Color
 
 ```typescript
-ops.setStrokingGray(g)      // Stroke grayscale (G)
-ops.setNonStrokingGray(g)   // Fill grayscale (g)
-ops.setStrokingRGB(r, g, b) // Stroke RGB (RG)
-ops.setNonStrokingRGB(r, g, b)  // Fill RGB (rg)
-ops.setStrokingCMYK(c, m, y, k)  // Stroke CMYK (K)
-ops.setNonStrokingCMYK(c, m, y, k)  // Fill CMYK (k)
-ops.setStrokingColorSpace(cs)    // Set stroke color space (CS)
-ops.setNonStrokingColorSpace(cs) // Set fill color space (cs)
-ops.setStrokingColorN(name)      // Set stroke pattern (SCN)
-ops.setNonStrokingColorN(name)   // Set fill pattern (scn)
+ops.setStrokingGray(g); // Stroke grayscale (G)
+ops.setNonStrokingGray(g); // Fill grayscale (g)
+ops.setStrokingRGB(r, g, b); // Stroke RGB (RG)
+ops.setNonStrokingRGB(r, g, b); // Fill RGB (rg)
+ops.setStrokingCMYK(c, m, y, k); // Stroke CMYK (K)
+ops.setNonStrokingCMYK(c, m, y, k); // Fill CMYK (k)
+ops.setStrokingColorSpace(cs); // Set stroke color space (CS)
+ops.setNonStrokingColorSpace(cs); // Set fill color space (cs)
+ops.setStrokingColorN(name); // Set stroke pattern (SCN)
+ops.setNonStrokingColorN(name); // Set fill pattern (scn)
 ```
 
 ### Line Style
 
 ```typescript
-ops.setLineWidth(w)         // Line width (w)
-ops.setLineCap(cap)         // 0=butt, 1=round, 2=square (J)
-ops.setLineJoin(join)       // 0=miter, 1=round, 2=bevel (j)
-ops.setMiterLimit(limit)    // Miter limit ratio (M)
-ops.setDashPattern(array, phase)  // Dash pattern (d)
+ops.setLineWidth(w); // Line width (w)
+ops.setLineCap(cap); // 0=butt, 1=round, 2=square (J)
+ops.setLineJoin(join); // 0=miter, 1=round, 2=bevel (j)
+ops.setMiterLimit(limit); // Miter limit ratio (M)
+ops.setDashPattern(array, phase); // Dash pattern (d)
 ```
 
 ### Text
 
 ```typescript
-ops.beginText()             // Begin text object (BT)
-ops.endText()               // End text object (ET)
-ops.setFont(name, size)     // Set font (Tf)
-ops.moveText(tx, ty)        // Position text (Td)
-ops.setTextMatrix(a, b, c, d, e, f)  // Text matrix (Tm)
-ops.showText(string)        // Show text (Tj)
+ops.beginText(); // Begin text object (BT)
+ops.endText(); // End text object (ET)
+ops.setFont(name, size); // Set font (Tf)
+ops.moveText(tx, ty); // Position text (Td)
+ops.setTextMatrix(a, b, c, d, e, f); // Text matrix (Tm)
+ops.showText(string); // Show text (Tj)
 ```
 
 ### XObjects and Shading
 
 ```typescript
-ops.paintXObject(name)      // Draw XObject (Do)
-ops.paintShading(name)      // Paint shading (sh)
+ops.paintXObject(name); // Draw XObject (Do)
+ops.paintShading(name); // Paint shading (sh)
 ```
 
 ---
@@ -146,7 +145,7 @@ import { Matrix, ops } from "@libpdf/core";
 
 const matrix = Matrix.identity()
   .translate(200, 300)
-  .rotate(45)  // degrees
+  .rotate(45) // degrees
   .scale(2, 1.5);
 
 page.drawOperators([
@@ -162,14 +161,14 @@ Or use raw matrix components:
 
 ```typescript
 // Translation: move 100 points right, 200 points up
-ops.concatMatrix(1, 0, 0, 1, 100, 200)
+ops.concatMatrix(1, 0, 0, 1, 100, 200);
 
 // Scale: 2x horizontal, 0.5x vertical
-ops.concatMatrix(2, 0, 0, 0.5, 0, 0)
+ops.concatMatrix(2, 0, 0, 0.5, 0, 0);
 
 // Rotation: 45 degrees around origin
-const angle = 45 * Math.PI / 180;
-ops.concatMatrix(Math.cos(angle), Math.sin(angle), -Math.sin(angle), Math.cos(angle), 0, 0)
+const angle = (45 * Math.PI) / 180;
+ops.concatMatrix(Math.cos(angle), Math.sin(angle), -Math.sin(angle), Math.cos(angle), 0, 0);
 ```
 
 ---
@@ -183,7 +182,7 @@ Create linear or radial gradients with color stops:
 ```typescript
 // CSS-style: angle + length
 const gradient = pdf.createLinearGradient({
-  angle: 90,  // 0=up, 90=right, 180=down, 270=left
+  angle: 90, // 0=up, 90=right, 180=down, 270=left
   length: 200,
   stops: [
     { offset: 0, color: rgb(1, 0, 0) },
@@ -194,7 +193,7 @@ const gradient = pdf.createLinearGradient({
 
 // Or explicit coordinates
 const axial = pdf.createAxialShading({
-  coords: [0, 0, 200, 0],  // x0, y0, x1, y1
+  coords: [0, 0, 200, 0], // x0, y0, x1, y1
   stops: [
     { offset: 0, color: rgb(0, 0, 1) },
     { offset: 1, color: rgb(1, 0, 1) },
@@ -206,7 +205,7 @@ const axial = pdf.createAxialShading({
 
 ```typescript
 const radial = pdf.createRadialShading({
-  coords: [100, 100, 0, 100, 100, 80],  // x0, y0, r0, x1, y1, r1
+  coords: [100, 100, 0, 100, 100, 80], // x0, y0, r0, x1, y1, r1
   stops: [
     { offset: 0, color: rgb(1, 1, 1) },
     { offset: 1, color: rgb(0, 0, 0) },
@@ -234,9 +233,7 @@ page.drawOperators([
 // Or wrap in a pattern for PathBuilder
 const pattern = pdf.createShadingPattern({ shading: gradient });
 
-page.drawPath()
-  .rectangle(50, 200, 200, 100)
-  .fill({ pattern });
+page.drawPath().rectangle(50, 200, 200, 100).fill({ pattern });
 ```
 
 ---
@@ -282,9 +279,7 @@ const pattern = pdf.createImagePattern({
   height: 50,
 });
 
-page.drawPath()
-  .circle(200, 400, 80)
-  .fill({ pattern });
+page.drawPath().circle(200, 400, 80).fill({ pattern });
 ```
 
 ### Gradient Pattern
@@ -387,23 +382,23 @@ Restrict drawing to a region:
 ```typescript
 page.drawOperators([
   ops.pushGraphicsState(),
-  
+
   // Define clip region (circle)
   ops.moveTo(200, 300),
   // ... circle path using bezier curves
   ops.clip(),
-  ops.endPath(),  // Required after clip
-  
+  ops.endPath(), // Required after clip
+
   // Everything here is clipped to the circle
   ops.paintShading(gradientName),
-  
-  ops.popGraphicsState(),  // Clipping is restored
+
+  ops.popGraphicsState(), // Clipping is restored
 ]);
 ```
 
 <Callout type="info">
-  Always follow `ops.clip()` with a path-painting operator. Use `ops.endPath()` 
-  to discard the path, or `ops.fill()` to both clip and fill.
+  Always follow `ops.clip()` with a path-painting operator. Use `ops.endPath()` to discard the path,
+  or `ops.fill()` to both clip and fill.
 </Callout>
 
 ---
@@ -444,7 +439,7 @@ const page = pdf.addPage();
 
 // Create button gradient
 const gradient = pdf.createLinearGradient({
-  angle: 180,  // top to bottom
+  angle: 180, // top to bottom
   length: 40,
   stops: [
     { offset: 0, color: rgb(0.4, 0.6, 1) },
@@ -475,7 +470,8 @@ page.drawOperators([
 ]);
 
 // Rounded rectangle path
-page.drawPath()
+page
+  .drawPath()
   .moveTo(110, 700)
   .lineTo(250, 700)
   .curveTo(255, 700, 260, 705, 260, 710)

content/docs/api/pdf-page.mdx

@@ -570,9 +570,9 @@ For advanced graphics operations, PDFPage provides methods to emit raw operators
 
 Emit raw PDF operators to the page content stream.
 
-| Param       | Type         | Description                 |
-| ----------- | ------------ | --------------------------- |
-| `operators` | `Operator[]` | Array of operators to emit  |
+| Param       | Type         | Description                |
+| ----------- | ------------ | -------------------------- |
+| `operators` | `Operator[]` | Array of operators to emit |
 
 ```typescript
 import { ops } from "@libpdf/core";
@@ -588,8 +588,8 @@ page.drawOperators([
 ```
 
 <Callout type="warn">
-  The caller is responsible for valid operator sequences. Invalid sequences
-  may produce corrupted PDFs.
+  The caller is responsible for valid operator sequences. Invalid sequences may produce corrupted
+  PDFs.
 </Callout>
 
 ---
@@ -598,8 +598,8 @@ page.drawOperators([
 
 Register a font resource and return its operator name.
 
-| Param  | Type                           | Description        |
-| ------ | ------------------------------ | ------------------ |
+| Param  | Type                                 | Description      |
+| ------ | ------------------------------------ | ---------------- |
 | `font` | `EmbeddedFont \| Standard14FontName` | Font to register |
 
 **Returns**: `string` - Resource name (e.g., `"F0"`)
@@ -623,9 +623,9 @@ page.drawOperators([
 
 Register an image resource and return its operator name.
 
-| Param   | Type       | Description        |
-| ------- | ---------- | ------------------ |
-| `image` | `PDFImage` | Embedded image     |
+| Param   | Type       | Description    |
+| ------- | ---------- | -------------- |
+| `image` | `PDFImage` | Embedded image |
 
 **Returns**: `string` - Resource name (e.g., `"Im0"`)
 
@@ -647,8 +647,8 @@ page.drawOperators([
 
 Register a shading (gradient) resource and return its operator name.
 
-| Param     | Type         | Description  |
-| --------- | ------------ | ------------ |
+| Param     | Type         | Description      |
+| --------- | ------------ | ---------------- |
 | `shading` | `PDFShading` | Shading resource |
 
 **Returns**: `string` - Resource name (e.g., `"Sh0"`)
@@ -699,8 +699,8 @@ page.drawOperators([
 
 Register an extended graphics state and return its operator name.
 
-| Param   | Type          | Description    |
-| ------- | ------------- | -------------- |
+| Param   | Type           | Description    |
+| ------- | -------------- | -------------- |
 | `state` | `PDFExtGState` | Graphics state |
 
 **Returns**: `string` - Resource name (e.g., `"GS0"`)
@@ -728,8 +728,8 @@ page.drawOperators([
 
 Register a Form XObject or embedded page and return its operator name.
 
-| Param     | Type                              | Description      |
-| --------- | --------------------------------- | ---------------- |
+| Param     | Type                                | Description         |
+| --------- | ----------------------------------- | ------------------- |
 | `xobject` | `PDFFormXObject \| PDFEmbeddedPage` | XObject to register |
 
 **Returns**: `string` - Resource name (e.g., `"Fm0"`)