fix: validate that breadcrumbs must be between 0-100

Source/BugsnagConfiguration.h

@@ -136,9 +136,10 @@ typedef NS_OPTIONS(NSUInteger, BSGErrorType) {
 @property(retain, nullable) NSString *appType;
 
 /**
- * The maximum number of breadcrumbs to keep and sent to Bugsnag.
- * By default, we'll keep and send the 25 most recent breadcrumb log
- * messages.
+ * Sets the maximum number of breadcrumbs which will be stored. Once the threshold is reached,
+ * the oldest breadcrumbs will be deleted.
+ *
+ * By default, 25 breadcrumbs are stored: this can be amended up to a maximum of 100.
  */
 @property NSUInteger maxBreadcrumbs;
 

Source/BugsnagConfiguration.m

@@ -370,7 +370,12 @@ - (NSUInteger)maxBreadcrumbs {
 }
 
 - (void)setMaxBreadcrumbs:(NSUInteger)capacity {
-    self.breadcrumbs.capacity = capacity;
+    if (capacity >= 0 && capacity <= 100) {
+        self.breadcrumbs.capacity = capacity;
+    } else {
+        bsg_log_err(@"Invalid configuration value detected. Option maxBreadcrumbs "
+                    "should be an integer between 0-100. Supplied value is %lu", capacity);
+    }
 }
 
 /**

Tests/BugsnagConfigurationTests.m

@@ -546,6 +546,36 @@ - (void)testSettingPersistUser {
     XCTAssertTrue(config.persistUser);
 }
 
+// =============================================================================
+// MARK: - Max Breadcrumb
+// =============================================================================
+
+- (void)testMaxBreadcrumb {
+    BugsnagConfiguration *config = [[BugsnagConfiguration alloc] initWithApiKey:DUMMY_APIKEY_32CHAR_1];
+    XCTAssertEqual(25, config.maxBreadcrumbs);
+
+    // alter to valid value
+    config.maxBreadcrumbs = 10;
+    XCTAssertEqual(10, config.maxBreadcrumbs);
+
+    // alter to max value
+    config.maxBreadcrumbs = 100;
+    XCTAssertEqual(100, config.maxBreadcrumbs);
+
+    // alter to min value
+    config.maxBreadcrumbs = 0;
+    XCTAssertEqual(0, config.maxBreadcrumbs);
+
+    // alter to negative value
+    config.maxBreadcrumbs = -1;
+    XCTAssertEqual(0, config.maxBreadcrumbs);
+
+    // alter to negative value (overflows)
+    config.maxBreadcrumbs = 500;
+    XCTAssertEqual(0, config.maxBreadcrumbs);
+}
+
+
 // =============================================================================
 // MARK: - Other tests
 // =============================================================================