[vector_graphics_compiler] fix: handle parsing stroke-width with an invalid value (flutter#8004)

There is some issue while calling parseDouble from the original repo of this package [issue link](dnfield/vector_graphics#209 (comment)).  I suggest a fix to change the return of **parseDouble** to always double.tryParse so that it will return `null` instead of throwing an error if it parses an invalid String

Fixes flutter#158819

Issue: [link](dnfield/vector_graphics#209 (comment))

Author: fransdhinta

packages/vector_graphics_compiler/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.16
+
+* Sets stroke-width to 1 by default when an invalid value is parsed instead of throwing an exception.
+
 ## 1.1.15
 
 * Fixes a bug where empty tags caused the parser to crash.

packages/vector_graphics_compiler/lib/src/svg/parser.dart

@@ -1587,7 +1587,7 @@ class SvgParser {
       cap: _parseCap(rawStrokeCap, null),
       join: _parseJoin(rawLineJoin, null),
       miterLimit: parseDouble(rawMiterLimit),
-      width: parseDoubleWithUnits(rawStrokeWidth),
+      width: parseDoubleWithUnits(rawStrokeWidth, tryParse: true),
       dashArray: _parseDashArray(rawStrokeDashArray),
       dashOffset: _parseDashOffset(rawStrokeDashOffset),
       hasPattern: hasPattern,

packages/vector_graphics_compiler/pubspec.yaml

@@ -2,7 +2,7 @@ name: vector_graphics_compiler
 description: A compiler to convert SVGs to the binary format used by `package:vector_graphics`.
 repository: https://github.com/flutter/packages/tree/main/packages/vector_graphics_compiler
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+vector_graphics%22
-version: 1.1.15
+version: 1.1.16
 
 executables:
   vector_graphics_compiler:

packages/vector_graphics_compiler/test/parser_test.dart

@@ -704,6 +704,87 @@ void main() {
     ]);
   });
 
+  test('stroke-width with invalid value', () {
+    const String svg =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="invalid"/></svg>';
+
+    final VectorInstructions instructions = parseWithoutOptimizers(svg);
+
+    expect(instructions.paints, const <Paint>[
+      Paint(
+          stroke: Stroke(color: Color(0xff0000ff)),
+          fill: Fill(color: Color(0xffff0000))),
+    ]);
+
+    expect(instructions.paths, <Path>[
+      Path(
+        commands: const <PathCommand>[
+          MoveToCommand(100.0, 10.0),
+          LineToCommand(180.0, 10.0),
+          LineToCommand(180.0, 90.0),
+          LineToCommand(100.0, 90.0),
+          CloseCommand(),
+        ],
+      ),
+    ]);
+  });
+
+  test('stroke-width with unit value', () {
+    const SvgTheme theme = SvgTheme();
+    const double ptConversionFactor = 96 / 72;
+
+    const String svg_px =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="1px"/></svg>';
+    const String svg_pt =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="1pt"/></svg>';
+    const String svg_ex =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="1ex"/></svg>';
+    const String svg_em =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="1em"/></svg>';
+    const String svg_rem =
+        '<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><path d="M100 10 H180 V90 H100 Z" fill="#ff0000" stroke="#0000ff" stroke-width="1rem"/></svg>';
+
+    final VectorInstructions instructionsPx = parseWithoutOptimizers(svg_px);
+    final VectorInstructions instructionsPt = parseWithoutOptimizers(svg_pt);
+    final VectorInstructions instructionsEx = parseWithoutOptimizers(svg_ex);
+    final VectorInstructions instructionsEm = parseWithoutOptimizers(svg_em);
+    final VectorInstructions instructionsRem = parseWithoutOptimizers(svg_rem);
+
+    expect(instructionsPx.paints, <Paint>[
+      const Paint(
+          stroke: Stroke(color: Color(0xff0000ff), width: 1.0),
+          fill: Fill(color: Color(0xffff0000))),
+    ]);
+
+    expect(instructionsPt.paints, <Paint>[
+      const Paint(
+          stroke:
+              Stroke(color: Color(0xff0000ff), width: 1 * ptConversionFactor),
+          fill: Fill(color: Color(0xffff0000))),
+    ]);
+
+    expect(instructionsEx.paints, <Paint>[
+      Paint(
+          stroke: Stroke(
+              color: const Color(0xff0000ff), width: 1.0 * theme.xHeight),
+          fill: const Fill(color: Color(0xffff0000))),
+    ]);
+
+    expect(instructionsEm.paints, <Paint>[
+      Paint(
+          stroke: Stroke(
+              color: const Color(0xff0000ff), width: 1.0 * theme.fontSize),
+          fill: const Fill(color: Color(0xffff0000))),
+    ]);
+
+    expect(instructionsRem.paints, <Paint>[
+      Paint(
+          stroke: Stroke(
+              color: const Color(0xff0000ff), width: 1.0 * theme.fontSize),
+          fill: const Fill(color: Color(0xffff0000))),
+    ]);
+  });
+
   test('Dashed path', () {
     final VectorInstructions instructions = parseWithoutOptimizers(
       '''