fix: one wording for an empty password field on every screen (closes #265)

tests/passwordMessages.test.js

@@ -1,4 +1,4 @@
-// One wording for one condition (issue #172).
+// One wording for one condition (issues #172 and #265).
 //
 // Every screen that asks for the password decrypts the vault itself, and
 // each one used to write its own sentence for the same failure: the send
@@ -21,6 +21,15 @@
 // call site is read back to its own catch handler and the prose that
 // handler shows the user must be the canonical sentence and nothing else
 // — which fails on a novel wording, not only on a known-superseded one.
+//
+// The empty-password condition (#265) is pinned the same way and off the
+// same call sites: the private key export screen said "Password is
+// required." where the other five said "Please enter your password." Each
+// decrypt's password variable is walked back to the guard that rejects it
+// when blank, and the prose that guard shows must be the canonical
+// sentence. Anchoring on the decrypt keeps the wallet-creation screen out
+// of the set: an empty field there is a password being CHOSEN, a
+// different condition with its own wording.
 
 const fs = require("fs");
 const path = require("path");
@@ -28,6 +37,7 @@ const path = require("path");
 const SRC = path.join(__dirname, "..", "src");
 
 const CANONICAL = "That password is incorrect. Please try again.";
+const CANONICAL_EMPTY = "Please enter your password.";
 
 // Wordings this repo has actually shipped for the same condition. This is
 // a secondary, whole-file sweep for stragglers outside a decrypt handler;
@@ -36,6 +46,7 @@ const CANONICAL = "That password is incorrect. Please try again.";
 const SUPERSEDED = [
     "Wrong password.",
     "That password is not correct. Please try again.",
+    "Password is required.",
 ];
 
 function jsFilesUnder(dir) {
@@ -149,6 +160,71 @@ function handlerMessages(file, callOffset, label) {
         .filter((v) => v.includes(" "));
 }
 
+// The identifier a decrypt call passes as its password, which is what the
+// empty-field guard for that screen tests.
+function passwordArg(masked, callOffset, label) {
+    const open = callOffset + "decryptWithPassword".length;
+    const args = [];
+    let depth = 0;
+    let start = open + 1;
+    for (let i = open; i < masked.length; i++) {
+        const c = masked[i];
+        if (c === "(" || c === "[" || c === "{") depth += 1;
+        else if (c === ")" || c === "]" || c === "}") {
+            depth -= 1;
+            if (depth === 0) {
+                args.push(masked.slice(start, i));
+                break;
+            }
+        } else if (c === "," && depth === 1) {
+            args.push(masked.slice(start, i));
+            start = i + 1;
+        }
+    }
+    const arg = (args[1] ?? "").trim();
+    if (!/^[A-Za-z_$][\w$]*$/.test(arg))
+        throw new Error(`${label}: password argument is not a name: ${arg}`);
+    return arg;
+}
+
+// Innermost block enclosing the decrypt that also declares its password
+// variable — the handler the screen's submit button runs, which is where
+// the empty-field guard lives.
+function declaringBlock(masked, callOffset, ident, label) {
+    const declared = new RegExp(`\\b(?:const|let|var)\\s+${ident}\\s*=`);
+    let at = callOffset;
+    for (;;) {
+        const open = enclosingBlockStart(masked, at);
+        if (open === -1) throw new Error(`${label}: nothing declares ${ident}`);
+        const end = blockEnd(masked, open);
+        if (declared.test(masked.slice(open, end))) return [open, end];
+        at = open - 1;
+    }
+}
+
+// The prose the empty-field guard puts in front of the user. Exactly one
+// guard per handler is required: two would mean the condition is answered
+// in more than one place and this would be pinning only one of them.
+function emptyGuardMessages(file, callOffset, label) {
+    const { masked, strings } = scan(fs.readFileSync(file, "utf8"));
+    const ident = passwordArg(masked, callOffset, label);
+    const [from, to] = declaringBlock(masked, callOffset, ident, label);
+    const guard = new RegExp(`if\\s*\\(\\s*!\\s*${ident}\\s*\\)\\s*\\{`, "g");
+    const opens = [];
+    let m;
+    while ((m = guard.exec(masked.slice(from, to))) !== null)
+        opens.push(from + m.index + m[0].length - 1);
+    if (opens.length !== 1)
+        throw new Error(
+            `${label}: expected one empty-${ident} guard, found ${opens.length}`,
+        );
+    const close = blockEnd(masked, opens[0]);
+    return strings
+        .filter((s) => s.offset >= opens[0] && s.offset < close)
+        .map((s) => s.value)
+        .filter((v) => v.includes(" "));
+}
+
 // The call sites are found, not listed: the file layout moves (the private
 // key export was in addressDetail.js when #172 was filed and is its own
 // view now), and a hardcoded list would quietly stop covering a screen it
@@ -187,8 +263,9 @@ describe("password failure messages", () => {
         });
     });
 
-    test("the canonical message is a full sentence", () => {
+    test("the canonical messages are full sentences", () => {
         expect(CANONICAL).toMatch(/^[A-Z][^]*\.$/);
+        expect(CANONICAL_EMPTY).toMatch(/^[A-Z][^]*\.$/);
     });
 
     // Exact equality, per call site: a message that is merely different
@@ -203,6 +280,15 @@ describe("password failure messages", () => {
         },
     );
 
+    test.each(sites.map((s) => [s.label, s]))(
+        "%s answers an empty password field with the canonical sentence",
+        (label, site) => {
+            expect(emptyGuardMessages(site.file, site.offset, label)).toEqual([
+                CANONICAL_EMPTY,
+            ]);
+        },
+    );
+
     test.each(files.map((f) => [path.relative(SRC, f), f]))(
         "%s carries no superseded wording",
         (_rel, file) => {