separate webdriver launch from other logic

Signed-off-by: Andrei Gherghescu <8067229+andrei-ng@users.noreply.github.com>

Author: andrei-ng

.github/workflows/build.yml

@@ -44,6 +44,8 @@ jobs:
           components: clippy
           targets: wasm32-unknown-unknown
       # lint plotly_static for all features
+      - run: cargo check -p plotly_static
+      - run: cargo test -p plotly_static build_without_driver_feature_returns_error
       - run: cargo clippy -p plotly_static --features geckodriver,webdriver_download -- -D warnings -A deprecated
       - run: cargo clippy -p plotly_static --features chromedriver,webdriver_download -- -D warnings -A deprecated
       # lint the main library workspace for non-wasm target

plotly_static/README.md

@@ -63,7 +63,7 @@ serde_json = "1.0"
 
 ### Feature Flags
 
-- To use static export, enable exactly one of the driver features below.
+- To use static export at runtime, enable exactly one of the driver features below.
 - `chromedriver`: Use Chromedriver and Chrome/Chromium browser for rendering and export
 - `geckodriver`: Use Geckodriver Firefox browser for rendering for rendering and export
 - `webdriver_download`: Auto-download the chosen WebDriver binary

plotly_static/build.rs

@@ -200,7 +200,7 @@ fn setup_driver(config: &WebdriverDownloadConfig) -> Result<()> {
     Ok(())
 }
 
-#[cfg(all(feature = "chromedriver", not(feature = "geckodriver")))]
+#[cfg(feature = "chromedriver")]
 fn get_chrome_path() -> Result<PathBuf> {
     if let Ok(chrome_path) = env::var(BROWSER_BIN_PATH_ENV) {
         let path = PathBuf::from(&chrome_path);

plotly_static/src/lib.rs

@@ -61,7 +61,7 @@
 //!
 //! ### Driver Features
 //!
-//! To use static export, enable one of the following features:
+//! For compile time only, no specific feature must be provided. However, to use static export at runtime, one of the below features must be enabled.
 //!
 //! - `chromedriver`: Use Chrome/Chromium for rendering
 //! - `geckodriver`: Use Firefox for rendering
@@ -304,6 +304,9 @@ use crate::template::{image_export_js_script, pdf_export_js_script};
 mod template;
 mod webdriver;
 
+#[cfg(not(any(feature = "chromedriver", feature = "geckodriver")))]
+const DRIVER_FEATURE_REQUIRED: &str = "Static image export at runtime requires enabling either the 'chromedriver' or 'geckodriver' feature.";
+
 /// Supported image formats for static image export.
 ///
 /// This enum defines all the image formats that can be exported from Plotly
@@ -649,6 +652,7 @@ impl StaticExporterBuilder {
     }
 
     /// Create a new WebDriver instance based on the spawn_webdriver flag
+    #[cfg(any(feature = "chromedriver", feature = "geckodriver"))]
     fn create_webdriver(&self) -> Result<WebDriver> {
         let port = self.webdriver_port;
         let in_async = tokio::runtime::Handle::try_current().is_ok();
@@ -689,16 +693,22 @@ impl StaticExporterBuilder {
     ///     .expect("Failed to build AsyncStaticExporter");
     /// ```
     pub fn build_async(&self) -> Result<AsyncStaticExporter> {
-        let wd = self.create_webdriver()?;
-        Ok(AsyncStaticExporter {
-            webdriver_port: self.webdriver_port,
-            webdriver_url: self.webdriver_url.clone(),
-            webdriver: wd,
-            offline_mode: self.offline_mode,
-            pdf_export_timeout: self.pdf_export_timeout,
-            webdriver_browser_caps: self.webdriver_browser_caps.clone(),
-            webdriver_client: None,
-        })
+        #[cfg(not(any(feature = "chromedriver", feature = "geckodriver")))]
+        return Err(anyhow!(DRIVER_FEATURE_REQUIRED));
+
+        #[cfg(any(feature = "chromedriver", feature = "geckodriver"))]
+        {
+            let wd = self.create_webdriver()?;
+            Ok(AsyncStaticExporter {
+                webdriver_port: self.webdriver_port,
+                webdriver_url: self.webdriver_url.clone(),
+                webdriver: wd,
+                offline_mode: self.offline_mode,
+                pdf_export_timeout: self.pdf_export_timeout,
+                webdriver_browser_caps: self.webdriver_browser_caps.clone(),
+                webdriver_client: None,
+            })
+        }
     }
 }
 
@@ -779,7 +789,7 @@ impl StaticExporter {
     /// # Examples
     ///
     /// ```no_run
-    /// 
+    ///
     /// // This example requires a running WebDriver (chromedriver/geckodriver) and a browser.
     /// // It cannot be run as a doc test.
     ///
@@ -842,7 +852,7 @@ impl StaticExporter {
     /// # Examples
     ///
     /// ```no_run
-    /// 
+    ///
     /// // This example requires a running WebDriver (chromedriver/geckodriver) and a browser.
     /// // It cannot be run as a doc test.
     /// use plotly_static::{StaticExporterBuilder, ImageFormat};
@@ -1128,9 +1138,7 @@ impl AsyncStaticExporter {
     fn build_webdriver_caps(&self) -> Result<Capabilities> {
         #[cfg(not(any(feature = "chromedriver", feature = "geckodriver")))]
         {
-            Err(anyhow!(
-                "Static image export requires enabling either the 'chromedriver' or 'geckodriver' feature."
-            ))
+            Err(anyhow!(DRIVER_FEATURE_REQUIRED))
         }
         #[cfg(any(feature = "chromedriver", feature = "geckodriver"))]
         {
@@ -1348,6 +1356,15 @@ mod tests {
         let _ = env_logger::try_init();
     }
 
+    #[test]
+    #[cfg(not(any(feature = "chromedriver", feature = "geckodriver")))]
+    fn build_without_driver_feature_returns_error() {
+        match StaticExporterBuilder::default().build_async() {
+            Err(e) => assert_eq!(e.to_string(), DRIVER_FEATURE_REQUIRED),
+            Ok(_) => panic!("expected build to fail without a driver feature"),
+        }
+    }
+
     // Helper to generate unique ports for parallel tests
     #[cfg(not(feature = "debug"))]
     fn get_unique_port() -> u32 {