feat: support subexpressions in partials arguments (#140)

Author: jmjuanes

README.md

@@ -732,9 +732,9 @@ console.log(result); // --> "Users: John Doe and Alice Smith"
 
 ### Subexpressions  
 
-> Added in `v0.30.0`. Supported in helpers in `v0.37.0`.
+> Added in `v0.30.0`. Supported in helpers and partials in `v0.37.0`.
 
-Subexpressions allow you to evaluate a function call inside another function call or helper. They are written using parentheses, and can be used anywhere a normal function argument is allowed. Example:
+Subexpressions allow you to evaluate a function call inside another function call, helpers, or partials. They are written using parentheses, and can be used anywhere a normal function argument is allowed. Example:
 
 ```hbs
 {{=sum (sum 3 4) 3}}
@@ -757,6 +757,12 @@ Subexpressions can be used in helpers also:
 {{#sayHello name=(concat "John" "Doe")}}{{/sayHello}}
 ```
 
+And in partials:
+
+```hbs
+{{>heading text=(concat "Hello" "World")}}
+``` 
+
 #### Nested subexpressions
 
 Subexpressions can be nested to any depth:
@@ -789,7 +795,7 @@ You can reference variables or paths normally:
 
 #### Limitations
 
-- Subexpressions are currently supported in **functions** (`{{=...}}`) and **helpers** (`{{# ...}}`).
+- Subexpressions are currently supported in **functions** (`{{=...}}`), **helpers** (`{{# ...}}`), and **partials** (`{{> ...}}`).
 - Parentheses must be balanced; malformed expressions will throw an error.
 
 

index.js

@@ -173,7 +173,7 @@ const compile = (ctx, tokens, output, data, state, index = 0, section = "") => {
             }
         }
         else if (tokens[i].startsWith(">")) {
-            const [t, args, opt] = parseArgs(tokens[i].replace(/^>{1,2}/, ""), data, state);
+            const [t, args, opt] = parseArgs(tokens[i].replace(/^>{1,2}/, ""), data, state, ctx.functions);
             const j = i + 1, blockContent = []; // to store partial block content
             if (tokens[i].startsWith(">>")) {
                 i = compile(ctx, tokens, blockContent, data, state, i + 1, t);

test.js

@@ -213,6 +213,30 @@ describe("templating", () => {
             };
             assert.equal(m(`{{>foo "tag1" "tag2" "tag3"}}`, {}, {partials}), "Tags: tag1,tag2,tag3,");
         });
+
+        it("should support subexpressions in positional arguments", () => {
+            const options = {
+                functions: {
+                    concat: params => params.args.join(" "),
+                },
+                partials: {
+                    foo: "Hello {{this}}!",
+                },
+            };
+            assert.equal(m(`{{>foo (concat "John" "Doe")}}`, {}, options), "Hello John Doe!");
+        });
+
+        it("should support subexpressions in key-value arguments", () => {
+            const options = {
+                functions: {
+                    concat: params => params.args.join(" "),
+                },
+                partials: {
+                    foo: "Hello {{this.name}}!",
+                },
+            };
+            assert.equal(m(`{{>foo name=(concat "John" "Doe")}}`, {}, options), "Hello John Doe!");
+        });
     });
 
     describe("{{>> xyz}}", () => {
@@ -492,7 +516,7 @@ describe("templating", () => {
             assert.equal(m("{{#greet}}{{/greet}}", data, options), "Hello Bob!");
         });
 
-        it("shoudl support accessing helper content using the @helper variable", () => {
+        it("should support accessing helper content using the @helper variable", () => {
             const options = {
                 helpers: {
                     foo: params => params.fn({value: "bar"}),