feat: add partial blocks (#32)

README.md

@@ -142,9 +142,28 @@ const result = m("User: {{>user userName=name userEmail=email }}", data, {partia
 
 Please note that providing keyword arguments and a custom context to a partial is not supported. On this situation, the partial will be evaluated only with the custom context.
 
+#### Partial blocks
+
+> This feature was added in `v0.16.0`.
+
+You can pass a block to a partial using a greather than symbol `>>` followed by the partial name to start the partial block, and a slash followed by the partial name to end the partial block. The provided block content will be available in the `@content` variable.
+
+Example:
+
+```javascript
+const options = {
+    partials: {
+        foo: "Hello {{@content}}!",
+    },
+};
+
+const result = m("{{>>foo}}Bob{{/foo}}", {}, options);
+// Output: 'Hello Bob!'
+```
+
 ### Inline partials
 
-> Added in `v0.16.0`.
+> This feature was added in `v0.16.0`.
 
 Inline partials allows you to define partials directly in your template. Use the plus symbol `+` followed by the partial name to start the partial definition, and end the partial definition with a slash `/` followed by the partial name. For example, `{{<foo}}` begins a partial definition called `foo`, and `{{/foo}}` ends it.
 

index.js

@@ -118,10 +118,15 @@ const create = (template = "", options = {}) => {
                 i = i + lastIndex + 1;
             }
             else if (tokens[i].startsWith(">")) {
-                const [t, args, opt] = parseArgs(tokens[i].slice(1), context, vars);
+                const [t, args, opt] = parseArgs(tokens[i].replace(/^>{1,2}/, ""), context, vars);
+                const blockContent = []; // to store partial block content
+                if (tokens[i].startsWith(">>")) {
+                    i = compile(tokens, blockContent, context, vars, i + 1, t);
+                }
                 if (typeof partials[t] === "string") {
                     const newCtx = args.length > 0 ? args[0] : (Object.keys(opt).length > 0 ? opt : context);
-                    compile(tokenize(partials[t]), output, newCtx, vars, 0, "");
+                    const newVars = {...vars, content: blockContent.join("")};
+                    compile(tokenize(partials[t]), output, newCtx, newVars, 0, "");
                 }
             }
             else if (tokens[i].startsWith("=")) {

test.js

@@ -164,6 +164,16 @@ describe("templating", () => {
         });
     });
 
+    describe("{{>> xyz}}", () => {
+        it("should allow providing a block to the partial", () => {
+            const partials = {
+                foo: "Hello {{@content}}!",
+            };
+
+            assert.equal(m("{{>>foo}}Bob{{/foo}}", {}, {partials}), "Hello Bob!");
+        });
+    });
+
     describe("{{#each }}", () => {
         it("should do nothing if value is not an array or object", () => {
             assert.equal(m("x{{#each values}}{{.}}{{/each}}x", {values: null}), "xx");