diff --git a/bin/presubmit.sh b/bin/presubmit.sh
new file mode 100755
index 0000000..509647e
--- /dev/null
+++ b/bin/presubmit.sh
@@ -0,0 +1,15 @@
+#! /usr/bin/env bash
+
+echo "Presubmit: Running Prettier...";
+prettier --write src || exit 1;
+
+echo "Presubmit: Running ESLint...";
+eslint --fix src --max-warnings=0 || exit 1;
+
+echo "Presubmit: Building...";
+react-scripts build || exit 1;
+
+echo "Presubmit: Running all tests...";
+react-scripts test --all --watchAll=false --coverage || exit 1;
+
+echo "Presubmit succeeded. Remember to commit any changes."
\ No newline at end of file
diff --git a/package.json b/package.json
index 0fa36f2..abcd17e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "groundhog",
-  "version": "0.10.9",
+  "version": "0.10.10",
   "homepage": "https://charredutensil.github.io/groundhog",
   "private": true,
   "dependencies": {
@@ -23,11 +23,12 @@
     "test": "react-scripts test",
     "predeploy": "react-scripts build",
     "deploy": "gh-pages -d build",
-    "presubmit": "prettier --write src && eslint --fix src --max-warnings=0 && react-scripts build && react-scripts test --all",
+    "presubmit": "bin/presubmit.sh",
     "eject": "react-scripts eject",
     "gen": "tsx bin/groundhog-gen",
     "architect-stats": "tsx bin/architect-stats",
-    "lore-dump": "tsx bin/lore-dump"
+    "lore-dump": "tsx bin/lore-dump",
+    "update-goldens": "UPDATE_GOLDENS=1 react-scripts test --all --watchAll=false"
   },
   "eslintConfig": {
     "extends": [
diff --git a/src/core/architects/utils/script.test.ts b/src/core/architects/utils/script.test.ts
index 637ad3f..52d9e65 100644
--- a/src/core/architects/utils/script.test.ts
+++ b/src/core/architects/utils/script.test.ts
@@ -1,4 +1,6 @@
-import { sanitizeString } from "./script";
+import goldenTest from "../../test_utils/golden";
+import { PreprogrammedCavern } from "../../transformers/04_ephemera/03_preprogram";
+import { mkScriptBuilder, mkVars, sanitizeString } from "./script";
 
 describe("escapeString", () => {
   it("handles the empty string", () => {
@@ -23,3 +25,171 @@ describe("escapeString", () => {
     );
   });
 });
+
+describe("ScriptBuilder", () => {
+  const cavern = {} as PreprogrammedCavern;
+
+  it("declares variables", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.declareArrow("arw");
+    sb.declareBuilding("bld");
+    sb.declareCreature("cr");
+    sb.declareInt("num", 42);
+    sb.declareString("str", "Message!");
+    expect(sb.build()).toEqual(`\
+arrow arw
+building bld
+creature cr
+int num=42
+string str="Message!"`);
+  });
+
+  it("declares an event", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.event("foo", "crystals+=1;");
+    expect(sb.build()).toEqual(`\
+foo::;
+crystals+=1;
+`);
+  });
+
+  it("declares a simple if trigger", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.if("crystals>10", "crystals-=5;");
+    expect(sb.build()).toEqual("if(crystals>10)[crystals-=5]");
+  });
+
+  it("declares a simple when trigger", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.when("crystals>50", "crystals-=1;");
+    expect(sb.build()).toEqual("when(crystals>50)[crystals-=1]");
+  });
+
+  it("creates an anonymous event chain to handle multiple statements", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.if("crystals>10", "wait:5;", "crystals-=5;");
+    expect(sb.build()).toEqual(`\
+if(crystals>10)[t0]
+t0::;
+wait:5;
+crystals-=5;
+`);
+  });
+
+  it("creates an anonymous event chain to handle repeated triggers", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.when("ore>50", "ore-=20;");
+    sb.when("ore>50", "crystals+=1;");
+    expect(sb.build()).toEqual(`\
+when(ore>50)[tw0]
+tw0::;
+ore-=20;
+crystals+=1;
+`);
+  });
+
+  it("creates anonymous event chains to handle repeated triggers with multiple statements", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.when("ore>50", "ore-=20;");
+    sb.when("ore>50", "wait:5;", "crystals+=1;");
+    sb.when("ore>50", "wait:10;", "crystals+=1;");
+    expect(sb.build()).toEqual(`\
+when(ore>50)[tw2]
+tw2::;
+ore-=20;
+t0;
+t1;
+
+t0::;
+wait:5;
+crystals+=1;
+
+t1::;
+wait:10;
+crystals+=1;
+`);
+  });
+
+  it("handles if and when triggers on the same condition 1", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.if("ore>50", "msg:msgFirstAlchemy;");
+    sb.when("ore>50", "ore-=20;", "wait:5;", "crystals+=1;");
+    expect(sb.build()).toEqual(`\
+int tf0=0
+if(tf0>0)[msg:msgFirstAlchemy]
+when(ore>50)[tw2]
+tw2::;
+tf0=1;
+t1;
+
+t1::;
+ore-=20;
+wait:5;
+crystals+=1;
+`);
+  });
+
+  it("handles if and when triggers on the same condition 2", () => {
+    const sb = mkScriptBuilder(cavern);
+    sb.if("ore>50", "shake:1;", "msg:msgFirstAlchemy;");
+    sb.when("ore>50", "ore-=20;");
+    expect(sb.build()).toEqual(`\
+int tf0=0
+if(tf0>0)[t1]
+t1::;
+shake:1;
+msg:msgFirstAlchemy;
+
+when(ore>50)[tw2]
+tw2::;
+tf0=1;
+ore-=20;
+`);
+  });
+
+  goldenTest("fizzbuzz", () => {
+    // This code is bad but idk - it's more about testing the builder.
+
+    const sb = mkScriptBuilder(cavern);
+    const v = mkVars("fbz", [
+      "n",
+      "lock",
+      "m",
+      "three",
+      "five",
+      "msgFizz",
+      "msgBuzz",
+      "msgFizzBuzz",
+    ]);
+    sb.declareInt(v.n, 0);
+    sb.declareInt(v.m, 0);
+    sb.declareInt(v.lock, 0);
+    sb.declareInt(v.three, 0);
+    sb.declareInt(v.five, 0);
+
+    sb.when("enter:1,1", `${v.lock}+=1;`);
+    sb.when(
+      `${v.lock}==1`,
+
+      `pan:${v.three},${v.five};`,
+
+      `${v.n}+=1;`,
+      `${v.m}=0;`,
+
+      `${v.three}+=1;`,
+      `((${v.three}==3))${v.m}=1;`,
+      `((${v.three}>=3))${v.three}-=3;`,
+
+      `${v.five}+=1;`,
+      `((${v.five}==5))${v.m}+=2;`,
+      `((${v.five}>=5))${v.five}-=5;`,
+
+      `((${v.m}==1))msg:${sb.declareString(v.msgFizz, "Fizz")};`,
+      `((${v.m}==2))msg:${sb.declareString(v.msgBuzz, "Buzz")};`,
+      `((${v.m}==3))msg:${sb.declareString(v.msgFizzBuzz, "Fizz Buzz")};`,
+
+      `${v.lock}=0;`,
+    );
+    return sb.build();
+  });
+});
diff --git a/src/core/architects/utils/script.ts b/src/core/architects/utils/script.ts
index 5c3a26d..a136c79 100644
--- a/src/core/architects/utils/script.ts
+++ b/src/core/architects/utils/script.ts
@@ -118,9 +118,9 @@ export type ScriptBuilder = {
 };
 
 type Trigger = {
-  kind: "if" | "when";
   condition: string;
-  bodies: `${string};`[];
+  ifs: `${string};`[];
+  whens: `${string};`[];
 };
 
 type BuildableScriptBuilder = ScriptBuilder & { build(): string };
@@ -148,20 +148,39 @@ export function mkScriptBuilder(
     }
     const tx: Trigger | undefined = triggers.byCondition[condition];
     if (tx) {
-      if (tx.kind !== kind) {
-        throw new Error(
-          `Attempted to redefine trigger \`${tx.kind}(${condition})\` as a \`${kind}\` trigger`,
-        );
-      }
-      triggers.byCondition[condition].bodies.push(body);
+      triggers.byCondition[condition][`${kind}s`].push(body);
       return;
     }
-    const t: Trigger = { kind, condition, bodies: [body] };
+    const t: Trigger =
+      kind === "if"
+        ? { condition, ifs: [body], whens: [] }
+        : { condition, ifs: [], whens: [body] };
     triggers.inOrder.push(t);
     triggers.byCondition[condition] = t;
   }
 
-  function buildTrigger({ kind, condition, bodies }: Trigger) {
+  function buildTrigger({ condition, ifs, whens }: Trigger) {
+    if (ifs.length && whens.length) {
+      // If there are both ifs and whens, need to trigger them separately.
+      const v = `tf${uid++}`;
+      return [
+        `int ${v}=0`,
+        buildTriggerHelper("if", `${v}>0`, ifs),
+        buildTriggerHelper("when", condition, [`${v}=1;`, ...whens]),
+      ].join("\n");
+    } else if (ifs.length) {
+      return buildTriggerHelper("if", condition, ifs);
+    } else if (whens.length) {
+      return buildTriggerHelper("when", condition, whens);
+    }
+    return "";
+  }
+
+  function buildTriggerHelper(
+    kind: "if" | "when",
+    condition: Trigger["condition"],
+    bodies: `${string};`[],
+  ) {
     const calls: `${string};`[] = [];
     const extra: string[] = [];
     bodies.forEach((body) => {
diff --git a/src/core/e2e_tests/golden.ts b/src/core/test_utils/golden.ts
similarity index 90%
rename from src/core/e2e_tests/golden.ts
rename to src/core/test_utils/golden.ts
index 201cdf5..1d7a45a 100644
--- a/src/core/e2e_tests/golden.ts
+++ b/src/core/test_utils/golden.ts
@@ -11,7 +11,7 @@ const updateGoldenFile = async (filePath: string, actual: string) => {
 };
 
 const goldenTest = async (name: string, fn: () => string) => {
-  const filePath = path.resolve(__dirname, `${GOLDEN_DIR}/${name}.dat`);
+  const filePath = path.resolve(__dirname, GOLDEN_DIR, name);
   test(name, async () => {
     const actual = fn();
     if (process.env[UPDATE_GOLDENS]) {
diff --git a/src/core/e2e_tests/goldens/building_zoo.dat b/src/core/test_utils/goldens/building_zoo.dat
similarity index 99%
rename from src/core/e2e_tests/goldens/building_zoo.dat
rename to src/core/test_utils/goldens/building_zoo.dat
index 3dd6aa6..abe7739 100644
--- a/src/core/e2e_tests/goldens/building_zoo.dat
+++ b/src/core/test_utils/goldens/building_zoo.dat
@@ -1,7 +1,7 @@
 comments{
   Cavern generated by groundHog [VERSION]
   https://github.com/charredUtensil/groundhog
-  initialContext: {}
+  initialContext = {}
 }
 info{
 rowcount:14
diff --git a/src/core/e2e_tests/goldens/entity_zoo.dat b/src/core/test_utils/goldens/entity_zoo.dat
similarity index 99%
rename from src/core/e2e_tests/goldens/entity_zoo.dat
rename to src/core/test_utils/goldens/entity_zoo.dat
index 0086849..6423a9d 100644
--- a/src/core/e2e_tests/goldens/entity_zoo.dat
+++ b/src/core/test_utils/goldens/entity_zoo.dat
@@ -1,7 +1,7 @@
 comments{
   Cavern generated by groundHog [VERSION]
   https://github.com/charredUtensil/groundhog
-  initialContext: {}
+  initialContext = {}
 }
 info{
 rowcount:14
diff --git a/src/core/test_utils/goldens/fizzbuzz b/src/core/test_utils/goldens/fizzbuzz
new file mode 100644
index 0000000..e63b9a2
--- /dev/null
+++ b/src/core/test_utils/goldens/fizzbuzz
@@ -0,0 +1,24 @@
+int fbz_n=0
+int fbz_m=0
+int fbz_lock=0
+int fbz_three=0
+int fbz_five=0
+string fbz_msgFizz="Fizz"
+string fbz_msgBuzz="Buzz"
+string fbz_msgFizzBuzz="Fizz Buzz"
+when(enter:1,1)[fbz_lock+=1]
+when(fbz_lock==1)[t0]
+t0::;
+pan:fbz_three,fbz_five;
+fbz_n+=1;
+fbz_m=0;
+fbz_three+=1;
+((fbz_three==3))fbz_m=1;
+((fbz_three>=3))fbz_three-=3;
+fbz_five+=1;
+((fbz_five==5))fbz_m+=2;
+((fbz_five>=5))fbz_five-=5;
+((fbz_m==1))msg:fbz_msgFizz;
+((fbz_m==2))msg:fbz_msgBuzz;
+((fbz_m==3))msg:fbz_msgFizzBuzz;
+fbz_lock=0;
diff --git a/src/core/e2e_tests/goldens/mvp.dat b/src/core/test_utils/goldens/mvp.dat
similarity index 98%
rename from src/core/e2e_tests/goldens/mvp.dat
rename to src/core/test_utils/goldens/mvp.dat
index 88f87a9..e751159 100644
--- a/src/core/e2e_tests/goldens/mvp.dat
+++ b/src/core/test_utils/goldens/mvp.dat
@@ -1,7 +1,7 @@
 comments{
   Cavern generated by groundHog [VERSION]
   https://github.com/charredUtensil/groundhog
-  initialContext: {}
+  initialContext = {}
 }
 info{
 rowcount:6
diff --git a/src/core/e2e_tests/serialize.test.ts b/src/core/transformers/04_ephemera/05_serialize.test.ts
similarity index 91%
rename from src/core/e2e_tests/serialize.test.ts
rename to src/core/transformers/04_ephemera/05_serialize.test.ts
index c09997e..8aa1cf5 100644
--- a/src/core/e2e_tests/serialize.test.ts
+++ b/src/core/transformers/04_ephemera/05_serialize.test.ts
@@ -1,5 +1,5 @@
-import { EAST, NORTH, Point, SOUTH, WEST } from "../common/geometry";
-import { MutableGrid } from "../common/grid";
+import { EAST, NORTH, Point, SOUTH, WEST } from "../../common/geometry";
+import { MutableGrid } from "../../common/grid";
 import {
   CANTEEN,
   DOCKS,
@@ -12,8 +12,8 @@ import {
   TELEPORT_PAD,
   TOOL_STORE,
   UPGRADE_STATION,
-} from "../models/building";
-import { Cavern } from "../models/cavern";
+} from "../../models/building";
+import { Cavern } from "../../models/cavern";
 import {
   BAT,
   CreatureFactory,
@@ -22,16 +22,16 @@ import {
   ROCK_MONSTER,
   SLIMY_SLUG,
   SMALL_SPIDER,
-} from "../models/creature";
-import { Erosion, Landslide } from "../models/hazards";
-import { MinerFactory } from "../models/miner";
-import { atCenterOfTile, position } from "../models/position";
-import { Tile } from "../models/tiles";
-import discover from "../transformers/03_plastic/01_discover";
-import fence from "../transformers/03_plastic/00_fence";
-import serialize from "../transformers/04_ephemera/05_serialize";
-import goldenTest from "./golden";
-import strataflux from "../transformers/03_plastic/03_strataflux";
+} from "../../models/creature";
+import { Erosion, Landslide } from "../../models/hazards";
+import { MinerFactory } from "../../models/miner";
+import { atCenterOfTile, position } from "../../models/position";
+import { Tile } from "../../models/tiles";
+import discover from "../03_plastic/01_discover";
+import fence from "../03_plastic/00_fence";
+import serialize from "./05_serialize";
+import goldenTest from "../../test_utils/golden";
+import strataflux from "../03_plastic/03_strataflux";
 import {
   CARGO_CARRIER,
   CHROME_CRUSHER,
@@ -46,7 +46,7 @@ import {
   TUNNEL_SCOUT,
   TUNNEL_TRANSPORT,
   VehicleFactory,
-} from "../models/vehicle";
+} from "../../models/vehicle";
 
 function fill<T>(
   grid: MutableGrid<T>,
@@ -107,7 +107,7 @@ function ds(args: Partial<Cavern>) {
   ).serialized.replace(/groundHog v\S+/, "groundHog [VERSION]");
 }
 
-goldenTest("mvp", () => {
+goldenTest("mvp.dat", () => {
   const crystals = new MutableGrid<number>();
   const tiles = new MutableGrid<Tile>();
   const openCaveFlags = new MutableGrid<true>();
@@ -133,7 +133,7 @@ goldenTest("mvp", () => {
   });
 });
 
-goldenTest("building_zoo", () => {
+goldenTest("building_zoo.dat", () => {
   const tiles = new MutableGrid<Tile>();
   const openCaveFlags = new MutableGrid<true>();
 
@@ -200,7 +200,7 @@ goldenTest("building_zoo", () => {
   });
 });
 
-goldenTest("entity_zoo", () => {
+goldenTest("entity_zoo.dat", () => {
   const tiles = new MutableGrid<Tile>();
   const openCaveFlags = new MutableGrid<true>();
 
diff --git a/src/core/transformers/04_ephemera/05_serialize.ts b/src/core/transformers/04_ephemera/05_serialize.ts
index 5a90aac..4af6838 100644
--- a/src/core/transformers/04_ephemera/05_serialize.ts
+++ b/src/core/transformers/04_ephemera/05_serialize.ts
@@ -33,7 +33,7 @@ function indent(it: string, prefix: string) {
 function comments(cavern: ProgrammedCavern) {
   return `Cavern generated by groundHog v${process.env.REACT_APP_VERSION}
 https://github.com/charredUtensil/groundhog
-initialContext: ${JSON.stringify(cavern.initialContext, null, 2)}`;
+initialContext = ${JSON.stringify(cavern.initialContext, null, 2)}`;
 }
 
 /**