Recognize GraphQL strings passed to JavaScript functions (#109)

Some JavaScript GraphQL frameworks use well-known functions rather than
tagged template literals. This change introduces basic support for these
cases via a new `g:graphql_javascript_functions` variable (["graphql"]).

This is implemented as a bit of a hack on top of the existing tagged
template support to avoid introducing new syntax regions:

    Tagged template:    graphql`
    Function call:      graphql(`
    Syntax pattern:     (graphql|graphql\()`

This is a good-enough place to start, and the overall approach gives us
room to iterate later if we want to revisit the implementation.

README.md

@@ -68,6 +68,22 @@ The list of recognized tag names is defined by the `g:graphql_javascript_tags`
 variable, which defaults to `["gql", "graphql", "Relay.QL"]`. This can also
 be set on a per-buffer basis using the `b:graphql_javascript_tags` variable.
 
+Untagged template literals passed as the first argument to specific functions
+can also be recognized. `g:graphql_javascript_functions` defines this list of
+functions, which defaults to `["graphql"]`. This list can also be set on a
+per-buffer basis using the `b:graphql_javascript_functions` variable.
+
+```javascript
+const query = graphql(`
+  {
+    user(id: ${uid}) {
+      firstName
+      lastName
+    }
+  }
+`;
+```
+
 You can also add a `# gql` or `# graphql` comment at the start of a template
 string to indicate that its contents should be considered GraphQL syntax.
 

after/syntax/javascript/graphql.vim

@@ -23,7 +23,8 @@
 
 call graphql#embed_syntax('GraphQLSyntax')
 
-let s:tags = '\%(' . join(graphql#javascript_tags(), '\|') . '\)'
+let s:functions = map(copy(graphql#javascript_functions()), 'v:val .. "("')
+let s:tags = '\%(' . join(graphql#javascript_tags() + s:functions, '\|') . '\)'
 
 if graphql#has_syntax_group('jsTemplateExpression')
   " pangloss/vim-javascript

after/syntax/typescript/graphql.vim

@@ -23,7 +23,8 @@
 
 call graphql#embed_syntax('GraphQLSyntax')
 
-let s:tags = '\%(' . join(graphql#javascript_tags(), '\|') . '\)'
+let s:functions = map(copy(graphql#javascript_functions()), 'v:val .. "("')
+let s:tags = '\%(' . join(graphql#javascript_tags() + s:functions, '\|') . '\)'
 
 exec 'syntax region graphqlTemplateString matchgroup=typescriptTemplate start=+' . s:tags . '\@20<=`+ skip=+\\`+ end=+`+ contains=@GraphQLSyntax,typescriptTemplateSubstitution extend'
 exec 'syntax match graphqlTaggedTemplate +' . s:tags . '\ze`+ nextgroup=graphqlTemplateString'

autoload/graphql.vim

@@ -60,6 +60,10 @@ function! graphql#has_syntax_group(group) abort
   return v:true
 endfunction
 
+function! graphql#javascript_functions() abort
+  return graphql#var('graphql_javascript_functions', ['graphql'])
+endfunction
+
 function! graphql#javascript_tags() abort
   return graphql#var('graphql_javascript_tags', ['gql', 'graphql', 'Relay.QL'])
 endfunction

doc/graphql.txt

@@ -25,6 +25,15 @@ supported.
 
                                                   *graphql-javascript-options*
 
+                                              *g:graphql_javascript_functions*
+                                              *b:graphql_javascript_functions*
+|g:graphql_javascript_functions|                               list of strings
+
+  Default: `["graphql"]`
+
+  This variable lists the JavaScript function names that will be recognized as
+  receiving GraphQL template literal strings as their first argument.
+
                                                    *g:graphql_javascript_tags*
                                                    *b:graphql_javascript_tags*
 |g:graphql_javascript_tags|                                    list of strings

test/javascript/default.vader

@@ -1,5 +1,6 @@
 Before:
-  Save g:graphql_javascript_tags
+  Save b:graphql_javascript_functions
+  Save b:graphql_javascript_tags
 
   setlocal shiftwidth=2
   source ../after/indent/javascript.vim
@@ -69,16 +70,46 @@ Execute (Syntax assertions):
   AssertEqual 'javascript', b:current_syntax
   AssertEqual 'graphqlName', SyntaxOf('user')
 
+Given javascript (Template literal with a graphql() function):
+  const query = graphql(`
+    {
+      user(id: ${uid}) {
+        firstName
+        lastName
+      }
+    }
+  `;
+
+Execute (Syntax assertions):
+  AssertEqual 'javascript', b:current_syntax
+  AssertEqual 'graphqlName', SyntaxOf('user')
+
 Given javascript (Template literal):
   const s = `text`;
 
 Execute (Untagged template literals aren't matched ):
   AssertNotEqual 'graphqlTemplateString', SyntaxOf('`')
 
+Given javascript (Custom function):
+  const query = gql(`
+    {
+      user(id: ${uid}) {
+        firstName
+        lastName
+      }
+    }
+  `;
+
+Execute (Function names can be customized):
+  let b:graphql_javascript_functions = ['gql']
+  source ../after/syntax/javascript/graphql.vim
+  AssertEqual 'javascript', b:current_syntax
+  AssertEqual 'graphqlName', SyntaxOf('user')
+
 Given javascript (Custom tag):
   const query = GraphQL.Tag`{}`;
 
 Execute (Tag names can be customized):
-  let g:graphql_javascript_tags = ['GraphQL.Tag']
+  let b:graphql_javascript_tags = ['GraphQL.Tag']
   source ../after/syntax/javascript/graphql.vim
   AssertEqual 'graphqlTaggedTemplate', SyntaxOf('GraphQL.Tag')

test/typescript/default.vader

@@ -1,5 +1,6 @@
 Before:
-  Save g:graphql_javascript_tags
+  Save b:graphql_javascript_functions
+  Save b:graphql_javascript_tags
 
   setlocal shiftwidth=2
   source ../after/indent/typescript.vim
@@ -48,7 +49,7 @@ Given typescript (Custom tag):
   const query = GraphQL.Tag`{}`;
 
 Execute (Tag names can be customized):
-  let g:graphql_javascript_tags = ['GraphQL.Tag']
+  let b:graphql_javascript_tags = ['GraphQL.Tag']
   source ../after/syntax/typescript/graphql.vim
   AssertEqual 'graphqlTaggedTemplate', SyntaxOf('GraphQL.Tag')
 
@@ -85,3 +86,17 @@ Given typescript (Template literal with `# graphql` comment):
 Execute (Syntax assertions):
   AssertEqual 'typescript', b:current_syntax
   AssertEqual 'graphqlName', SyntaxOf('user')
+
+Given typescript (Template literal with a graphql() function):
+  const query = graphql(`
+    {
+      user(id: ${uid}) {
+        firstName
+        lastName
+      }
+    }
+  `;
+
+Execute (Syntax assertions):
+  AssertEqual 'typescript', b:current_syntax
+  AssertEqual 'graphqlName', SyntaxOf('user')