chore(test): add template literal for trimming indentation

spec/support/utils.spec.ts

@@ -0,0 +1,14 @@
+import { trimIndentation } from "./utils.js";
+
+describe("Utils", () => {
+    it("trims indentation", () => {
+        expect(trimIndentation`\
+            Hello
+                world
+            123`
+        ).toBe(`\
+Hello
+    world
+123`);
+    });
+});

spec/support/utils.ts

@@ -0,0 +1,21 @@
+export function trimIndentation(strings: TemplateStringsArray) {   
+    const str = strings.toString();
+
+    // Count the number of spaces on the first line.
+    let numSpaces = 0;
+    while (str.charAt(numSpaces) == ' ' && numSpaces < str.length) {
+        numSpaces++;
+    }
+    
+    // Trim the indentation of the first line in all the lines.   
+    const lines = str.split("\n");
+    const output = []; 
+    for (let i=0; i<lines.length; i++) {
+        let numSpacesLine = 0;
+        while (str.charAt(numSpacesLine) == ' ' && numSpacesLine < str.length) {
+            numSpacesLine++;
+        }
+        output.push(lines[i].substring(numSpacesLine));
+    }
+    return output.join("\n");
+}