util: remove custom inspection function

This removes the deprecated custom inspection function and fixes
all tests accordingly.

Refs: https://github.com/nodejs/node/issues/15549

PR-URL: https://github.com/nodejs/node/pull/20722
Refs: https://github.com/nodejs/node/issues/15549
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 21 insertions, 70 deletions

diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index b80e932dd1..e3122d1b81 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -531,10 +531,10 @@ assert.strictEqual(util.inspect(-5e-324), '-5e-324');
   );
 }
 
-// GH-1941
+// https://github.com/nodejs/node-v0.x-archive/issues/1941
 assert.strictEqual(util.inspect(Object.create(Date.prototype)), 'Date {}');
 
-// GH-1944
+// https://github.com/nodejs/node-v0.x-archive/issues/1944
 {
   const d = new Date();
   d.toUTCString = null;
@@ -549,20 +549,20 @@ assert.strictEqual(util.inspect(Object.create(Date.prototype)), 'Date {}');
 }
 
 // Should not throw.
-const r = /regexp/;
-r.toString = null;
-util.inspect(r);
-
-// Bug with user-supplied inspect function returns non-string.
-util.inspect([{ inspect: () => 123 }]);
+{
+  const r = /regexp/;
+  r.toString = null;
+  util.inspect(r);
+}
 
-// GH-2225
+// See https://github.com/nodejs/node-v0.x-archive/issues/2225
 {
-  const x = { inspect: util.inspect };
-  assert.strictEqual(util.inspect(x).includes('inspect'), true);
+  const x = { [util.inspect.custom]: util.inspect };
+  assert(util.inspect(x).includes(
+    '[Symbol(util.inspect.custom)]: \n   { [Function: inspect]'));
 }
 
-// util.inspect should display the escaped value of a key.
+// `util.inspect` should display the escaped value of a key.
 {
   const w = {
     '\\': 1,
@@ -660,8 +660,8 @@ util.inspect({ hasOwnProperty: null });
 }
 
 {
-  // "customInspect" option can enable/disable calling inspect() on objects.
-  const subject = { inspect: () => 123 };
+  // "customInspect" option can enable/disable calling [util.inspect.custom]().
+  const subject = { [util.inspect.custom]: () => 123 };
 
   assert.strictEqual(
     util.inspect(subject, { customInspect: true }).includes('123'),
@@ -680,31 +680,6 @@ util.inspect({ hasOwnProperty: null });
     true
   );
 
-  // Custom inspect() functions should be able to return other Objects.
-  subject.inspect = () => ({ foo: 'bar' });
-
-  assert.strictEqual(util.inspect(subject), '{ foo: \'bar\' }');
-
-  subject.inspect = (depth, opts) => {
-    assert.strictEqual(opts.customInspectOptions, true);
-  };
-
-  util.inspect(subject, { customInspectOptions: true });
-}
-
-{
-  // "customInspect" option can enable/disable calling [util.inspect.custom]().
-  const subject = { [util.inspect.custom]: () => 123 };
-
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: true }).includes('123'),
-    true
-  );
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: false }).includes('123'),
-    false
-  );
-
   // A custom [util.inspect.custom]() should be able to return other Objects.
   subject[util.inspect.custom] = () => ({ foo: 'bar' });
 
@@ -718,42 +693,15 @@ util.inspect({ hasOwnProperty: null });
 }
 
 {
-  // [util.inspect.custom] takes precedence over inspect.
-  const subject = {
-    [util.inspect.custom]() { return 123; },
-    inspect() { return 456; }
-  };
-
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: true }).includes('123'),
-    true
-  );
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: false }).includes('123'),
-    false
-  );
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: true }).includes('456'),
-    false
-  );
-  assert.strictEqual(
-    util.inspect(subject, { customInspect: false }).includes('456'),
-    false
-  );
-}
-
-{
   // Returning `this` from a custom inspection function works.
-  assert.strictEqual(util.inspect({ a: 123, inspect() { return this; } }),
-                     '{ a: 123, inspect: [Function: inspect] }');
-
   const subject = { a: 123, [util.inspect.custom]() { return this; } };
   const UIC = 'util.inspect.custom';
   assert.strictEqual(util.inspect(subject),
                      `{ a: 123,\n  [Symbol(${UIC})]: [Function: [${UIC}]] }`);
 }
 
-// util.inspect with "colors" option should produce as many lines as without it.
+// Using `util.inspect` with "colors" option should produce as many lines as
+// without it.
 {
   function testLines(input) {
     const countLines = (str) => (str.match(/\n/g) || []).length;
@@ -1160,8 +1108,11 @@ util.inspect(process);
 
 // Setting custom inspect property to a non-function should do nothing.
 {
-  const obj = { inspect: 'fhqwhgads' };
-  assert.strictEqual(util.inspect(obj), "{ inspect: 'fhqwhgads' }");
+  const obj = { [util.inspect.custom]: 'fhqwhgads' };
+  assert.strictEqual(
+    util.inspect(obj),
+    "{ [Symbol(util.inspect.custom)]: 'fhqwhgads' }"
+  );
 }
 
 {