Addresses Copilot's round-18 review on #2035. Two suppressed comments, both
holes in my own recent fixes rather than in the original code.
1. Round 16's grouping keyed off the length-announcing lead byte alone, so
it accepted sequences RFC 3629 forbids -- and the comment claiming they
fell back to per-triplet counting was simply wrong. Measured on 05bbfe50:
x{+v:1} "%C0%80x" => "x%C0%80" overlong
"%E0%80%80x" => "x%E0%80%80" overlong
"%ED%A0%80x" => "x%ED%A0%80" UTF-16 surrogate
"%F4%90%80%80x" => "x%F4%90%80%80" past U+10FFFF
The lead-byte ranges are now the well-formed ones -- C2-DF, E0 only with
A0-BF, ED only with 80-9F, F0 only with 90-BF, F4 only with 80-8F -- so
each of the above falls back to one triplet, which is what the fallback
was always documented to do. The legal boundary cases (%E0%A0%80,
%ED%9F%BF, %F4%8F%BF%BF) are tested alongside, so tightening the ranges
cannot quietly start splitting valid characters.
2. The preview never ran the read's template validation. It expands
expression by expression, so `x://{a}}/{b}` with both fields filled
previewed `x://1}/2` -- a URI whose stray `}` makes every read refuse.
Validation moved into an exported `templateError` that both callers
consult, so they cannot drift. It subsumes the narrower rule round 12
added here ("leave the invalid part standing"), which still let the REST
of such a template expand: the refusal is per template, not per
expression, so the preview now shows the template verbatim -- literals
unencoded included, since half-normalizing an unreadable template invents
a string the server never published. Two existing tests asserted the
weaker behavior and now assert this one.
npm run ci passes.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-16 review on #2035. Two suppressed comments, both
real, and both refinements of fixes from the previous two rounds rather than
defects in the original code.
1. Round 11 settled on "a pct-encoded triplet counts as one character", but
a multi-octet character spans several triplets -- `%C3%A9` is one `é`.
Measured on a3dd8563:
x{+v:1} v = "%C3%A9x" => "x%C3" a lone lead byte, decoding to nothing
`prefixUnits` now recognizes a well-formed pct-encoded UTF-8 sequence from
its lead byte (RFC 3629: C2-DF two octets, E0-EF three, F0-F4 four;
continuations 80-BF), longest alternative first so a four-octet sequence
is not read as a two-octet one followed by loose triplets.
A malformed sequence -- a lead byte with too few continuations, or a stray
continuation -- matches no sequence alternative and falls back to
per-triplet counting. That is the conservative direction: it counts as
MORE units, so truncation keeps less rather than emitting octets that
were never in the value.
2. Round 14's per-value ceiling only covered the read. The panel calls
`previewUriTemplate` on every keystroke, and that path expands expression
by expression, so it reached the allocation-heavy encoders with the same
oversized value -- submission refused while the UI froze on the paste
anyway. Both paths now share one exported `valueLengthError`, checked
before any encoding happens.
npm run ci passes.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-12 review on #2035. Both halves are regressions
from my own round-10 rework, which replaced "expand a rewritten template
through the lenient expandUriTemplate" with a part-by-part assembly and so
lost two properties that implementation had for free. Reproduced on
c6fb6271:
previewUriTemplate("x://{v}", { v: "\ud800" }) => throws URIError
previewUriTemplate("x://{a,}", { a: "1" }) => "x://1"
The first is the worse one: the preview runs during render, so an escaping
throw unmounts the whole panel rather than disabling its button -- and an
unpaired surrogate is real input, since `encodeURIComponent` raises URIError
on one and a paste can deliver it. The panel already reports that case
properly through `tryExpandUriTemplate`; the display path now degrades to
the raw template instead of taking the panel down with it.
The second promised a URI the user could never send: `{a,}` is an invalid
template whose submission is refused, but `a` survives into the
expression's varspecs, so filling it previewed `x://1`. An invalid
expression is now left standing as written, which is what the rest of the
panel already says about it.
Tests for both, plus one asserting the valid expressions around an invalid
one still preview.
npm run ci passes.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-10 review on #2035. One inline comment, one
suppressed; both real.
1. Literals were copied through verbatim, but RFC 6570 3.1 requires them
pct-encoded on expansion -- the conformance case `café/{var}` expands to
`caf%C3%A9/value`. Measured on ef3f5e74 it produced `café/value`, raw
UTF-8 in the path; since this module replaced the SDK's expander for both
clients, nothing else was going to encode it. (The pinned SDK does not
either -- it returns `café/value` too -- so this is a gap we inherited
rather than introduced.)
`encodeLiteral` keeps reserved delimiters (a literal's `/`, `?` and `#`
are structure) and existing pct-triplets, and encodes the rest. A BRACE
passes through: it can only reach a literal from a malformed template,
where an unclosed `{` becomes trailing text, and `%7B` would leave a
string resembling neither the template nor anything the server can match.
This is also what removed the preview's placeholder machinery. No token
can survive a round trip now that literals are encoded, so the preview
assembles part by part instead -- `encodeLiteral` for literal runs,
`expandTemplateExpression` for filled expressions, `part.source` for the
rest. Both halves still come from the shared expander, so the preview
cannot promise a URI that submitting would not send, and the question of
what token could never collide with a server-supplied template is gone.
2. On the varname set I took the structural point rather than the
conclusion. `VARCHAR` is RFC-exact again; `-` and `~` moved into a
separately named `TOLERATED_VARCHAR` tier, and a name needing it parses
with `conforming: false`, surfaced on `TemplateVariable`.
So the grammar in the code says what the RFC says and the tolerance is
explicit and separately tested -- but the Inspector still expands
`{default-graph-uri}`, because real servers publish hyphenated names and
the SDK's matcher round-trips them. Refusing to read a resource that
demonstrably works is a worse failure for a debugging tool than expanding
a name the conformance suite would reject. A caller wanting RFC-exact
behavior refuses on the flag rather than re-deriving the grammar.
npm run ci passes.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-6 review on #2035.
`toString`, `constructor`, `valueOf` and `__proto__` are all valid RFC
6570 variable names -- `varname` allows ALPHA / DIGIT / `_` / pct-encoded
-- and every lookup here was a bare `values[name]`, which finds
`Object.prototype`'s member for each of them. Measured: `({})["toString"]
!== undefined` is true with typeof "function", and `({}["constructor"] ??
"").length` is 1.
So a *blank* `{?toString}` field read as supplied and expanded a function
body into the URI instead of omitting the expression, and
`hasRequiredValues([["constructor"]], {})` returned true because
`Object.length` is 1 -- a required group satisfied by nothing.
All reads now go through an own-property `readValue`, and the web
preview's filled-check uses `Object.hasOwn`. `expandExpression` carries
the value through its filter rather than re-reading it afterwards, so the
"is it defined" test and the read cannot disagree and nothing needs a
non-null assertion.
The remaining six findings were documentation drifting behind the code,
which matters here because the comments are the argument for why this
module exists:
- The web helper still described the SDK's second-`?`-to-`&` rewrite as
something the preview relies on. That was removed last round.
- Three places still named the CLI as a consumer. It has no template form
and passes an already-expanded `--uri` to `readResource`.
- The PR description still described the superseded architecture
(expansion delegated to the SDK), i.e. the opposite of what now ships.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-5 review on #2035 — eight suppressed comments,
all of them real.
The consequential one overturns behavior I copied from the SDK and
defended in two earlier rounds. RFC 6570 expands each expression
independently; it carries no cross-expression state. The SDK tracks
whether a query expression has already emitted and rewrites a later
`{?two}`'s `?` to `&`. That looks friendlier and is wrong, and its own
matcher says so: for `x{?one}{?two}` it expands to `x?one=1&two=2`, and
`match("x?one=1&two=2")` on that same template returns **null**, while
`match("x?one=1?two=2")` returns both variables. So the rewrite emitted a
URI the advertised template cannot match — #1919 one level up. A server
that wants a continuation advertises `{?one}{&two}`, which expands to `&`
and matches; producing that shape is the server's choice to declare, not
ours to infer.
Also:
- `{id:abc}` was silently treated as `{id}`, and a test codified it. RFC
6570's max-length is `%x31-39 0*3DIGIT`, so `{id:}`, `{id:0}`,
`{id:abc}` and `{id:10000}` are invalid templates rather than templates
with an ignorable modifier — and the SDK's constructor accepts them all,
so nothing else rejects them. Strict expansion now throws; lenient
returns the raw template. Discovery stays lenient so the panel still
renders rather than going blank.
- The TUI could submit `{a,b}` completely blank while the web panel
blocked the same request: ink-form has no way to express "any one of
these", so its members are left optional and the modal needs its own
group check. Added, with tests — it was also below the coverage gate
without them (functions 76.92%).
- Added the integration test the config never had: it resolves the
checked-in config and drives all four reads over a real transport, so a
misspelt preset fails there rather than only when someone runs the repro
by hand.
- "All three clients" was false. The CLI has no template form and its
`resources/read` passes the already-expanded `--uri` straight to
`readResource`, so nothing here runs for it. Corrected in the README,
AGENTS.md, and the module comment, and dropped a docblock still
describing the SDK-delegation path removed last round.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's round-2 review on #2035. It reported "no new comments"
but carried three *suppressed* ones; all three reproduced against the
pinned SDK.
1. The `;` path-parameter operator is absent from the SDK's operator list,
so `{;id}` parsed as a variable literally named ";id" and expanded to
nothing. Added the operator and its named expansion (`;a=1;b=2`).
2. An RFC 6570 prefix modifier was folded into the variable name: `{id:3}`
yielded a variable called "id:3" and expanded to nothing. Varspecs are
now parsed properly and the value truncated before encoding. Truncation
is by code point, since `String.prototype.slice` counts UTF-16 units and
would split an astral character into a lone surrogate.
For both of these the wrong URI is the lesser problem: a form has to
*name* the variables it asks the user to fill, so the panel was
rendering fields labelled `;id` and `id:3` that nobody could use.
3. Requiredness was applied per variable, but it is a property of the
*expression*: RFC 6570 drops undefined names from a multi-name
expression, so `{a,b}` with only `a` filled expands to `a`'s value --
the SDK does this too. The panel was refusing input the expander would
have accepted. `hasRequiredValues` now encodes "any one name in a
required group suffices", and such a field reads "Any one of: a, b"
rather than falsely claiming each is mandatory.
Two structural consequences, each pinned by a test:
- Takeover is now per TEMPLATE rather than per expression. Splicing
corrected fragments into a template the SDK re-expands would leave its
cross-expression `?`-to-`&` rewrite blind to the fragments already
resolved.
- Expansion is split into a strict variant that throws and a lenient one
that returns the raw template. `readResourceFromTemplate` wraps the
thrown error with the template name -- three pre-existing integration
tests assert that -- while the form must not throw on a server-supplied
template, since that would take out the panel on render. The strict
variant constructs the SDK template unconditionally, because that
construction is what validates syntax: otherwise `x://{;a}{b,c` would
take the own-expansion path and its unclosed tail would pass as literal
text with nothing objecting.
Signed-off-by: cliffhall <cliff@futurescale.com>
Addresses Copilot's review on #2035. All three findings reproduced against
the pinned SDK before acting.
1. `#` was misclassified as required. Measured: `x://a{#frag}` with no
`frag` expands to exactly `x://a`, a well-formed URI naming a real
resource -- unlike `{+path}` (`x://a/`) or a simple `{userId}`
(`file:///users//profile`), which leave an empty path segment. Moved `#`
into the omittable set; the required cases now assert what the URI
*becomes* when blank, so the rule is checked rather than asserted.
2. Delegating to the SDK did not actually give RFC 6570 expansion.
`UriTemplate.expandPart` takes an early `names.length > 1` branch that
raw-joins values, skipping both `encodeValue` and the operator prefix:
`x://{a,b}` with `a = "foo/bar"` expands to `x://foo/bar,q` -- the very
unencoded-slash defect this PR is about -- and `x://a{/p,q}` to
`x://ax y,z`. Only `?`/`&` are correct, being dispatched earlier.
Fixing that in the web client alone would have left the TUI and CLI
wrong, since `readResourceFromTemplate` expands through the same class.
So parse/classify/expand now live in `core/mcp/uriTemplate.ts` and both
call sites use it. The correction is surgical: a multi-name non-query
expression is expanded here and spliced in as literal text before the
SDK sees the template (safe -- both encoders escape `{`/`}`), while
every single-name and query expression still goes through the SDK
untouched. The preview applies the same correction, so it cannot
promise a URI that submitting would not send.
3. The showcase promised a blank `{?topic}` read that did not work.
`UriTemplate.match()` compiles `{?topic}` to a *required*
`\?topic=([^&]+)`, so `match("foobar://events")` returns null and the
read 404s. A real server exposes the unfiltered collection as its own
resource; the showcase now registers `foobar://events` so the
documented step resolves. Verified end to end through the CLI.
Signed-off-by: cliffhall <cliff@futurescale.com>
The Resources screen discovered and substituted template variables with a
bare `/\{(\w+)\}/g` regex, which is wrong two ways: it cannot see an
expression carrying an operator, so `foobar://events{?topic}` rendered no
input at all; and it splices the raw value in, so a `/`, `?`, `#`, `%`,
space or non-ASCII character in a simple `{topic}` landed unencoded and
changed the URI's structure -- `foo/bar` produced an extra path segment
that a conforming matcher rejects with `-32602 Resource not found`.
Delegate expansion to the SDK's `UriTemplate`, the same implementation
`InspectorClient.readResourceFromTemplate` (and so the TUI) already
expands through, so the two clients cannot disagree about what a template
means. The new `utils/uriTemplate` supplies only what that class does
not: which variables to render an input for, which of them a read cannot
proceed without, and a partially-expanded preview.
Required-ness follows the operator. Under `?`, `&`, `.` or `/` the whole
expression is omitted when the variable is undefined, so those fields are
marked Optional and reading with them blank is a legitimate request for
the unfiltered resource; under `""`, `+` or `#` the variable sits mid-URI,
so it stays required. Blank fields are dropped before expanding so an
untouched optional field reads as undefined rather than as the empty
string, which would expand to a valueless `?topic=`.
Adds the `rfc6570_templates` preset and a `rfc6570-templates-http.json`
showcase server serving the two templates from the issue.
Closes#1919
Signed-off-by: cliffhall <cliff@futurescale.com>
cliffhall