Add header option to CLI

Author: travismiller

graphql_client_cli/README.md

@@ -22,6 +22,7 @@ FLAGS:
 
 OPTIONS:
         --authorization <authorization>    Set the contents of the Authorizaiton header.
+        --header <headers>...              Specify custom headers. --header 'X-Name: Value'
         --output <output>                  Where to write the JSON for the introspected schema.
 
 ARGS:

graphql_client_cli/src/introspect_schema.rs

@@ -4,6 +4,7 @@ use reqwest;
 use reqwest::header::{HeaderMap, HeaderValue, ACCEPT, CONTENT_TYPE};
 use serde_json;
 use std::path::PathBuf;
+use std::str::FromStr;
 
 #[derive(GraphQLQuery)]
 #[graphql(
@@ -18,6 +19,7 @@ pub fn introspect_schema(
     location: &str,
     output: Option<PathBuf>,
     authorization: Option<String>,
+    headers: Vec<Header>,
 ) -> Result<(), failure::Error> {
     use std::io::Write;
 
@@ -35,6 +37,14 @@ pub fn introspect_schema(
     let client = reqwest::Client::new();
 
     let mut req_builder = client.post(location).headers(construct_headers());
+
+    for custom_header in headers {
+        req_builder = req_builder.header(
+            custom_header.name.as_str(),
+            custom_header.value.as_str(),
+        );
+    }
+
     if let Some(token) = authorization {
         req_builder = req_builder.bearer_auth(token.as_str());
     };
@@ -60,3 +70,82 @@ fn construct_headers() -> HeaderMap {
     headers.insert(ACCEPT, HeaderValue::from_static("application/json"));
     headers
 }
+
+#[derive(Debug, PartialEq)]
+pub struct Header {
+    name: String,
+    value: String,
+}
+
+impl FromStr for Header {
+    type Err = failure::Error;
+    
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        // error: colon required for name/value pair
+        if ! input.contains(":") {
+            return Err(format_err!("Invalid header input. A colon is required to separate the name and value. [{}]", input));
+        }
+
+        // split on first colon and trim whitespace from name and value
+        let name_value: Vec<&str> = input.splitn(2, ':').collect();
+        let name = name_value[0].trim();
+        let value = name_value[1].trim();
+
+        // error: field name must be
+        if name.len() == 0 {
+            return Err(format_err!("Invalid header input. Field name is required before colon. [{}]", input));
+        }
+        
+        // error: no whitespace in field name
+        if name.split_whitespace().count() > 1 {
+            return Err(format_err!("Invalid header input. Whitespace not allowed in field name. [{}]", input));
+        }
+
+        Ok(Self{name: name.to_string(), value: value.to_string()})
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_errors_invalid_headers() {
+        // https://tools.ietf.org/html/rfc7230#section-3.2
+
+        for input in vec![
+            "X-Name Value",   // error: colon required for name/value pair
+            ": Value",        // error: field name must be
+            "X Name: Value",  // error: no whitespace in field name
+            "X\tName: Value", // error: no whitespace in field name (tab)
+        ] {
+            let header = Header::from_str(input);
+
+            assert!(header.is_err(), "Expected error: [{}]", input);
+        }
+    }
+
+    #[test]
+    fn it_parses_valid_headers() {
+        // https://tools.ietf.org/html/rfc7230#section-3.2
+
+        let expected1 = Header{name: "X-Name".to_string(), value: "Value".to_string()};
+        let expected2 = Header{name: "X-Name".to_string(), value: "Value:".to_string()};
+
+        for (input, expected) in vec![
+            ("X-Name: Value", &expected1),  // ideal
+            ("X-Name:Value", &expected1),   // no optional whitespace
+            ("X-Name: Value ", &expected1), // with optional whitespace
+            ("X-Name:\tValue", &expected1), // with optional whitespace (tab)
+            ("X-Name: Value:", &expected2), // with colon in value
+            // not allowed per RFC, but we'll forgive
+            ("X-Name : Value", &expected1),
+            (" X-Name: Value", &expected1),
+        ] {
+            let header = Header::from_str(input);
+
+            assert!(header.is_ok(), "Expected ok: [{}]", input);
+            assert_eq!(header.unwrap(), *expected, "Expected equality: [{}]", input);
+        }
+    }
+}

graphql_client_cli/src/main.rs

@@ -39,6 +39,10 @@ enum Cli {
         /// Set the contents of the Authorizaiton header.
         #[structopt(long = "authorization")]
         authorization: Option<String>,
+        /// Specify custom headers.
+        /// --header 'X-Name: Value'
+        #[structopt(long = "header")]
+        headers: Vec<introspect_schema::Header>,
     },
     #[structopt(name = "generate")]
     Generate {
@@ -85,7 +89,13 @@ fn main() -> Result<(), failure::Error> {
             schema_location,
             output,
             authorization,
-        } => introspect_schema::introspect_schema(&schema_location, output, authorization),
+            headers,
+        } => introspect_schema::introspect_schema(
+            &schema_location,
+            output,
+            authorization,
+            headers,
+        ),
         Cli::Generate {
             additional_derives,
             deprecation_strategy,