feat: Cast booleans

Converts strings true/false, True/False, TRUE/FALSE, 1/0 to boolean if the default is boolean.
alecperkins · Mar 29, 2023 · a00c0b0 · a00c0b0
1 parent 8791182
commit a00c0b0
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Showing 2 changed files with 56 additions and 0 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -27,6 +27,20 @@ const conf: (
           _override = Number(override);
           break;
         }
+        case "boolean": {
+          if (override.toLowerCase() === "true") {
+            _override = true;
+          } else if (override.toLowerCase() === "false") {
+            _override = false;
+          } else if (override === "1") {
+            _override = true;
+          } else if (override === "0") {
+            _override = false;
+          } else {
+            _override = Boolean(override);
+          }
+          break;
+        }
         default: {
           _override = override;
         }

diff --git a/tests/index.test.ts b/tests/index.test.ts
@@ -35,6 +35,48 @@ describe("conf", () => {
     reset();
   });
 
+  test("doesn't convert numbers when not originally boolean", async () => {
+    const reset = overrideEnv({ MYVAL: "2" });
+    const config = conf({ MYVAL: "asdf" });
+    expect(config.MYVAL).not.toEqual(2);
+    reset();
+  });
+
+  test("doesn't convert booleans when not originally boolean", async () => {
+    const reset = overrideEnv({ MYVAL: "true" });
+    const config = conf({ MYVAL: "asdf" });
+    expect(config.MYVAL).not.toEqual(true);
+    reset();
+  });
+
+  test("casts json booleans", async () => {
+    const reset = overrideEnv({ MYVAL: "true" });
+    const config = conf({ MYVAL: false });
+    expect(config.MYVAL).toEqual(true);
+    reset();
+  });
+
+  test("casts capitalized booleans", async () => {
+    const reset = overrideEnv({ MYVAL: "True" });
+    const config = conf({ MYVAL: false });
+    expect(config.MYVAL).toEqual(true);
+    reset();
+  });
+
+  test("casts 0 booleans", async () => {
+    const reset = overrideEnv({ MYVAL: "0" });
+    const config = conf({ MYVAL: true });
+    expect(config.MYVAL).toEqual(false);
+    reset();
+  });
+
+  test("casts 1 booleans", async () => {
+    const reset = overrideEnv({ MYVAL: "1" });
+    const config = conf({ MYVAL: false });
+    expect(config.MYVAL).toEqual(true);
+    reset();
+  });
+
   test("reads from environment", async () => {
     const reset = overrideEnv({ MYVAL: "different" });
     const config = conf({ MYVAL: "testing" });